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  • Small enough to take into the field on long or short trips; contents are packaged into a small plastic case
  • Contains all necessary maintenance parts, including O-rings, inlet foam, inlet valve, outlet cap and silicone lubricant

Made in USA.

View all MSR Water Filter Accessories

REI membership


Best Use Backpacking
Rated 1 out of 5 by from Missing pieces This product *should* provide all the key components required to maintain the MSR MicroFilter. It doesn't. It does NOT contain the Umbrella Valve that, in my experience, is the component most prone to failure on the MSR MicroFilter. The umbrella value acts to maintain water pressure inside the chamber holding the ceramic core - it is therefore critical to ensuring water is pushed through the filter. Having it fail means that you are unable to maintain adequate water pressure. You will know when this is happening when you pump the handle and the MSR water clear water chamber (at the top of the unit) gradually fails to fill with water yet and there is apparent (and growing) pressure in the system. This is happening because both the clear chamber and ceramic chamber are becoming pressurized (ie the valve is leaking air back into the clear chamber) and you are unable to draw the next pump of water into the filter - drawing up water is necessary because, in the subsequent push down, it is the effective incompressibility of water that pushes it through the filter (if the clear chamber contains just air then the air is effectively just 'squeezed' and little/no water comes out of the filter). Net net: if you were expecting to buy this product to give you a complete set of replacement pieces for the MSR Micro Filter then think again. It does contain the other seals and maintenance pieces you might otherwise need. The umbrella valve is available separately from other retailers (unfortunately not from REI). Note to REI / REI customers - many thanks helping test out my water filter and for replacing my filter without charge. 5*s for you guys as always.
Date published: 2013-08-12
Rated 1 out of 5 by from Suoer Inflated price DO NOT BUY. this is and absolutely insane price for this item. the two o rings can be bought for less than a dollar each at any hard wear store, if you need a replacement check valve ball, just ask your friend who plays airsoft for a 6 mm BB, the little piece of foam and the silicone lube can be found pretty much anywhere for a small amount of money. sorry REI and MSR but as a pour college kid who loves to camp I can't sit and watch you charge [$] for four bucks worth of stuff.
Date published: 2008-02-06
Rated 2 out of 5 by from Where's the umbrella valve. I find it odd that this is marked "everything you need". When it is missing a very important part. The umbrella valve. Can't do much without it, so it is not really "everything you need".
Date published: 2013-06-23
Rated 3 out of 5 by from Overpriced overhaul kit This seems more like an overhaul kit than an emergency backup item, and if I could do it again I wouldn't buy it unless I planned to use it immediately. This filter is pretty rugged with highly oversized o-rings that can handle varied conditions and a fair bit of abuse, so I'm not sure this kit makes much sense. There are a few parts that may be susceptible to breakage, wear, or loss which aren't included, like the hinge pins. On the other hand, the piston o-ring and duckbill valve are susceptible to whatever you suck up the hose and the inlet foam has an important role in protecting those items. The silicone can be used between trips when you do a thorough disassembly and cleaning. The storage box is nice. Overall, the price is MUCH too high.
Date published: 2011-05-14
Rated 1 out of 5 by from How can they leave out the one part that fails? I can't understand why they chose to leave out the inexpensive, incredibly important umbrella valve. This makes no sense at all.
Date published: 2014-09-18
Rated 1 out of 5 by from Necessary parts not even in the kit! $20 for a few O-rings is ridiculous!! What I need is the umbrella gasket, which is the one part that is not part of this kit.
Date published: 2015-08-21
Rated 5 out of 5 by from A must-have for every backpacker. I am a biologist, and I hate rationing water. I will gladly carry a filter and several bottles rather than have to economize. This little kit is light and contains all the seals needed for the miniworks, plus the lube for the all-important pumping seal. I have one in the same bag as my filter and an extra in the pack. The world's best filter is no good if you don't maintain it, this cheap little kit will refresh an old one to perfect condition.
Date published: 2016-01-21
Rated 5 out of 5 by from Perfect Size I have this little kit tucked into a pocket in my pack when I go on extended hikes. Its just a smart thing to have. If you have the filter, its good to have a maintenance kit in case an o-ring splits or breaks. Its a small package and very light. Never had to use it yet, but its nice to have and nice to know its there when you are days away fresh water.
Date published: 2014-11-10
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Does REI have maintenance kits that include the duckbill intake valve and tiny o ring that insert into the intake valve spring?  Someone on my staff took apart the MSR and lost that tiny little valve that is on the inside of the mechanism.

Asked by: f350trk
Unfortunately we do not have any MSR kits that have the springs included. We would recommend contacting Cascade Designs (MSR).
Answered by: REIservice
Date published: 2016-09-20

Does the kit contain the Duck Bill? I need a replacement one.

Asked by: David Schuler
This maintenance kit does contain the duckbill valve.
Answered by: REIservice
Date published: 2016-09-22

Can someone tell me how many O-rings come with this kit? I've seen ads with as many as 5 and others with only 2 or 3.

Asked by: GlennT
This MSR maintenance kit comes with 5 different O-rings, each a different size.
Answered by: REIservice
Date published: 2015-09-20
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