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  • Ceramic/carbon Marathon™ EX element effectively removes bacteria and protozoa including giardia and cryptosporidia
  • Also removes unpleasant tastes and odors caused by organic compounds, such as iodine, chlorine and pesticides
  • Filter can be cleaned over and over for maximum field life with no tools required
  • AirSpring Accumulator™ increases filtration speed up to 1 liter per min.
  • Bottom screws onto an MSR Dromedary® Bag or Nalgene® water bottle for easy operation (both sold separately)
  • Easy disassembly lets you troubleshoot and maintain the MSR MiniWorks EX filter in the field

Made in USA.

Weight reported dry, without accessories.

View all MSR Pump Water Filters

REI membership


Best Use Backpacking
Filter Type Pump
Filter Medium Ceramic with carbon core
Removes/Destroys Protozoa and Bacteria
Pump Force 10.4 pounds
Pump Strokes Per Liter 85
Output 1 liters per minute
Housing Material Polyurethane
BPA Free Yes
Field Cleanable Yes
Dimensions 7.8 x 3.8 inches
Weight 14.6 ounces
Rated 5 out of 5 by from Earned my trust I used the MSR MiniWorks EX Filter on a backpacking trip in the Olympic National Park. It is pretty light and easy to set up and use. The river was not as clear as I would have liked it to be but the filter did not clog up and worked as promised. Clean-up was easy and could be done in the field if needed. The instruction booklet was easy to read and very detailed. It screws on to any wide mouth water bottle for easy operation. To be honest I was paranoid about getting sick because this is the first water filtration system I'd ever used but to my pleasant surprise it did not let me or my wife down.
Date published: 2010-07-18
Rated 5 out of 5 by from Great filtration system I very much like the MSR MiniWorks EX. I have used it from backpacking to Military field operations. It has never let me down. It does have some cons but are from diffrent water sources. In clear water, the filter pumps easily but i have used some nasty muddy water which will clog your filter much faster, but what would you expect, clean it and drive on. No matter how muddy, dirty, grimmy or nasty the water i am filtering from, the MSR MiniWorks EX has done its job, with no after taste and clear tasty water.
Date published: 2013-02-17
Rated 5 out of 5 by from Awesome little pump This little pump works amazingly well. I have owned it for 5+ years now, and have never needed to replace anything on it. I do meticulously maintain it per the owner's manual after each trip, which to be honest is kind of a pain, but is well worth the effort. My pump has been used for many liters of water, and have never had any issues with it. However, it is slow, much slower compared to my buddy's Katadyn. It is slow, and kind of awkward and difficult to pump, but does an amazing job filter the water which is what's really important. Be careful cleaning it in the field. It has little o-rings and pieces, and they can get easily lost leaving the pump useless.
Date published: 2017-02-08
Rated 5 out of 5 by from Superb filter! Have owned this filter for 9 years and use it in the field anywhere from 10-30 days every year. I have used it in conditions from the cleanest spring seeps to silty trenched driplines at the base of timberline snowbanks in the afternoons(looks like chocolate milk). It has NEVER failed to provide wonderfully purified water. I have had geardia before from purification systems that were not up to the task, but never an issue with this pump. It is a water filter so when it becomes more difficult to pump, you take it apart and clean it. The worse the quality of the water you are filtering, the more frequently it needs cleaned. I have had to replace the element, but that was because I dropped it on a rock. These elements will last a long time, and if you take proper care of this filter it will take care of you.
Date published: 2013-03-31
Rated 1 out of 5 by from Very Disappointing I bought this pump for a trip into the BWCAW(Boundary Waters). I couldn't believe how frequently I had to clean it. I could only get 3 liters of water before the ceramic element needed to be scrubbed down. The first liter went really fast, the second was slower but still decent for the most part, the third liter was a struggle to get. This was consistent on all lakes. The lakes were visibly clear and I was not near any swamps. The water that was pumped was great though. No odor or taste whatsoever. I see others have complained about the force needed to pump it but I didn't think it was bad. The maintenance is just too high to recommend this product though.
Date published: 2010-10-08
Rated 1 out of 5 by from Only if you like Cleaning Filters I bought this after reading all the good reviews and took it on a week long Kings Canyon backpacking trip with some friends. It worked great the first couple times but then I noticed the filter would quickly become clogged. I thought that was normal until I noticed that my friends water filter (of a different brand) never needed to be cleaned and he was done filling his bottle in 1 minute when it took me about 5! I thought his was broken but his water tasted just as good. Needless to say mine went to the bottom of the pack after the continuous cleaning got old and never saw the light of day again. If you like cleaning filters this is a great water filter.
Date published: 2009-03-02
Rated 2 out of 5 by from MSR ex vs. First Need Just back from 1 week in Sierras. Our party had an MSR EX (mine) and a First Need. I have always liked the field serviceable aspect of the MSR, but by the end of our trip, the MSR was pumping so slow, we had given up on it. It took 30 min to get 4 liters of water. We could have cleaned the MSR filter, but I did not bring a pad to do that, and really wasn't expecting to, given that we were out for 5 days. Meantime, the First need was still going quickly. About 10 min for 4 liters of water. Both had clean/new filters to start with, and we were obtaining water from reasonably clear lake water (ie, Duck lake). First Need won on this trip.
Date published: 2010-08-07
Rated 5 out of 5 by from LOVE IT If I could marry this thing I would. Here is my breakdown: PROS 1. Super lightweight. I used to have the old version which was .5 lbs heavier. 2. I've never gotten sick. I use this thing all the time and sometimes with very questionable water...I mean...nasty. 3. Super easy to maintain. Get the maintenance kit. Really this thing should come with it already but it doesn' buy it. Super peace of mind in the field. 4. Very nice design. This thing looks cool. Some of the other MSR models and other manufacturers products look dorky. This thing looks really cool. 5. Good bang for your pump. You don't feel like you're wasting time with each pump. Cons 1. I can't marry it. 2. The filtering element is delicate so you have to be careful. Don't let it freeze with water in it or you'll have a broken element. If that happens on the are in trouble. 3. I always have backup purification tablets just in case. Tips 1. Get some coffee filters and rubber bands to wrap around the hose inlet. It will pre filter the water and extend the life of your filter element. A coffee filter is way cheaper than a new element. 2. In case of really nasty, wonky water...have a bottle of water purification tablets and use them properly. Also some powdered juice mix packets to help remove the purification tablet flavor if you end up using the tablets. 3. Make sure you bring that maintenance kit AND properly maintain your filter as needed. Take care of it, it will take care of you. 4. FINALLY: These things are a value at the normal price but often they go on sale so keep that in mind when you are ready to buy. I hope you found this helpful.
Date published: 2013-05-16
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I have had a MiniWorks EX in storage for many years...never been used (part of an Earthquake preparedness kit). Now I want to take it on a backpacking trip. Is the cartridge still ok to use?  Asked another way, what is the shelf life of the cartridge?

Asked by: gregfree
The MiniWorks EX Water Filter will be just fine to use after years of storage. MSR recommends sterilizing the ceramic element after long periods of storage. Instructions for sterilization can be found on MSR's website. MSR does not list a shelf life for the ceramic element.
Answered by: REIservice
Date published: 2017-03-02

The inlet hose barb has broken on my unit. I can't find where to buy a replacement part for it. The MSR website doesn't list anything to buy.

Asked by: clemson61
I had an issue with mine that I needed a new duckbill and spring. I had lost mine in the field. I contacted MSR directly and they were great. They had a replacement shipped the following day. Get a hold of them. I believe they are called Cascade Designs 800-531-9531. Good luck
Answered by: gambillford
Date published: 2017-05-23

I have a new miniworks ex micro filter. I have read about placing the coffee filter on the inlet tube end. Upon viewing the sweetwater I see it has a screened inlet. Can i purchase that part and attach it to my filter?

Asked by: HuntBchSoCal
The screened prefilter for the MSR SweetWater can be purchased from MSR directly, but it is not compatible with the MiniWorks EX Water Filter.
Answered by: REIservice
Date published: 2016-07-26

Can this filter be used with an outlet hose (hose for clean water)? I know it screws onto Nalgenes but I was wondering if I could use it more like a traditional 2 hose pump system. Thanks!

Asked by: Steak
An output hose can be attached to the MiniWorks EX Water Filter. The output hose is not included with the filter.
Answered by: REIservice
Date published: 2016-07-06

Do adaptive devices need to be purchased with this product? It is not clear to me exactly how it works. I am thinking that I need an adapter for a Nalgene. Help? Thanks!

Asked by: Shneed
No adaptive devices need to be purchased. Simply drop the intake hose into the water source, screw the pump onto the opening of your Nalgene bottle or backpack bladder and pump. This is very convenient to have it connect like that when you are balancing on a rock trying to make sure you don't fall in the water!
Answered by: REIservice
Date published: 2016-04-27

Does the pump come with the mini 3M scrub pad? I didn't see it listed under specs or on the details page. However, I saw the scrub pad with the replacement cartridge.

Asked by: DebK
Yes, the MiniWorks EX Water Filter does come with the green scrub pad for cleaning the filter.
Answered by: REIservice
Date published: 2017-05-17

Is this filter compatible with a Platypus-type hydration system? If not, is an adapter available? 

Asked by: Spring Ahead
The MiniWorks EX Water Filter will not directly attach to Platypus reservoirs. Water can however be pumped directly into Platypus reservoirs from the MiniWorks. An adapter does not exist.
Answered by: REIservice
Date published: 2016-04-27

I'm interested in taking a trip to India. Would the purifier system be suitable for water treatment there and would the NIH recommended 4 drops of bleach per liter still be needed?

Asked by: RocKnocker
The MiniWorks would not be the best choice for international travel. The MiniWorks is a filter and not a purifier. It will remove protoza and bacteria but not viruses. The MSR SweetWater Water Purifier System would be a better choice.
Answered by: REIservice
Date published: 2017-03-02
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