Sea to Summit  Cool Grip X-Mug

I did a thorough test on this product for hot drinks. I did not test it for cold drinks. Sometimes I get free products to test, but this one I paid for all on my own. I did a side-by-side comparison of this cup compared to the Wal-Mart brand Ozark Trail collapsible cup. My first test: I filled both up to the top with hot tap water (about 130 deg F/54 deg C). I it was obvious that the StS cup was cooler on the outside to the touch compared to the OT cup. I let them sit for a while and continued to check--the pattern held. I did notice that the StS cup lost water temperature a little faster than the OT cup, 1-2 deg more after about 5 minutes. Not much... but some. I find that most poeple consume their hot drinks on campouts within that time period. My second test was comparing boiling water from a kettle. I poured boiling water into both cups about 3/4 full (what would be a typical "fill line" for most practical applications). I found that the OT cup was too hot to hold after about 5 seconds, but the StS cup I could hold indefinitely. Successful test, and a noticibable difference indeed! But the final test is a practical application: Can I use my preferred pourover coffee gear to make a cup of joe. I used the GSI Outdoors Ultralight Java Drip Coffee Maker (and a nice medium grind from Chock Full-o Nuts, my preferred coffee). I'm pleased to report it held up without a hitch and the pourover process worked just fine. In summary, the only downside to report is that the liquid in the cup loses temperature slightly faster than a typical collapsible, but it is superior in every other measure. I will add more to my gear inventory!

[This review was collected as part of a promotion.] I own several pieces from the X-line of cookware. The X-Mug was my latest addition for a November backpacking trip through Zion and Joshua Tree National Parks. I’d previously used a titanium mug, but it took up too much room in my pack. The silicone mug holds heat for long enough, and the walls weren’t too hot to hold. It packed down nicely inside my X-Bowl with the X-Pot Kettle while stashed away in a S2S dry sack. The measurement markings were small to read but might not have been so bad if I hadn’t left my reading glasses at the trailhead! Otherwise, together, it made a slick little mess kit.

Silicon rubber is one of the safest materials for hot liquids and not know to leach chemicals in any significant amount. It is not a petrochemical material. This cup keeps coffee hot, not indefinitely like a thermos, but long enough for most hikers and backpackers. I love it.

Sure, you could drink and eat out of your cook pot, but this doesn't add much space or weight (70 grams on my scale) to your cook set, and let's you drink your morning coffee and eat at the same time. Collapsed, the diameter is about the same size as an 8oz fuel canister, so if your pot can nest that inside of it, this will fit as well.

Light, multipurpose, and functional. The rim isn't silicone so it'll melt if you put it near/in fire, which happened because it is a fantastic lid for my cooking pot. But only on my stove from now on! As a mug it's not quite 16oz but definitely holds 12 comfortably. Also good as a small bowl for breakfast

The cup is a great idea. It packs down nicely, doesn’t burn your fingers while holding coffee, and has volume markings on the inside. However the third cup of coffee resulted in it leaking through the side of the cup making it unusable. Lasted about as long as a paper cup

This mug will stay fully collapsed as long as you hold it with both hands. Otherwise, it just pops out and defaults to ... a non-collapsible mug.

[This review was collected as part of a promotion.] I love this mug. I wasn’t sure I would, but I’m glad I gave it a try. It holds hot liquids without burning my hands, and I like the cool texture. It immediately became home to my daily green tea. I anticipate a future subject to climate emergency. The thought that I could easily take a favorite everyday mug with me wherever I go, by collapsing it down to a very lightweight disc, is a comfort. Plus, I can carry it with me and forego disposables. Love it. Have left it in the open position, so cannot speak to how it holds up upon repeated opening and collapsing over time. But so far so good.

I just poured boiling water and a cappuccino mix into the XMUG. Its ribs feel warm but not hot, and the rim does not get too hot. I find its 2 cup size "just right." It is stable, easy to hold, and reasonably light weight, especially compared to a ceramic cup. I've no trouble collapsing it. At 72 g / 2.5 oz., no doubt there are lighter options out there, but for something compact for hot drinks it's hard to beat.

I bought this in New York on my AT thru hike, and I used it all the way through VA (approximately 2 months). I ultimately sent it home because I decided to drink out of my cook pot instead, but I did miss this mug. It shows no sign of wear, insulated my hand from the heat well, and collapsed smoothly. When the cup was popped open it felt rather sturdy.