Detail Images

  • Sea To Summit - X-Mug Collapsible Mug - Grey
  • Sea To Summit - X-Mug Collapsible Mug - Lime Green
  • Sea To Summit - X-Mug Collapsible Mug - Berry

Current Color

  • Sea To Summit - X-Mug Collapsible Mug - Grey
  • Sea To Summit - X-Mug Collapsible Mug - Lime Green
  • Sea To Summit - X-Mug Collapsible Mug - Berry

Sea To Summit X-Mug Collapsible Mug


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    • Grey, One Size
    • Lime Green, One Size
    • Berry, One Size

    21 Reviews


    Now you can stop drinking coffee out of water bottles.

    From morning coffee to afternoon happy hour, the Sea To Summit X-Mug pops up to hold your favorite beverage, then folds flat for easy storage. This convenient mug features an accordion-style design and food-grade silicon sides, as well as a sturdy nylon top ring to maintain shape.
    • Item #STS0070

    Tech Specs

    silicone, nylon
    16 oz
    Claimed Weight
    2.7 oz
    Recommended Use
    camping, backpacking

    Tech Specs

    • Reviews
    • Q & A

    What do you think about this product?

    Have questions about this product?

    Great Coffee Cup

    • Familiarity: I've put it through the wringer

    I wanted a coffee cup that was lightweight and easy to stow away in my cooking kit. The X-Mug fit the bill, so I gave it a try... haven't turned back. I don't drink anything else out of it, it's simply my coffee cup. With that in mind, I can't speak to what others experienced with memory retention of past drinks that contaminate others with odd flavors. I like the fact that on a cool morning, I can warm my hands up nicely with a fresh cup of coffee by holding the mug around the silicone and the top outer ring provides a sturdy place to hold and drink the hot stuff without warming the hands at all. Sea to Summit did a great job with this one.

    Great Coffee Cup

    Perfect cup for the slopes

    • Familiarity: I've used it once or twice and have initial impressions

    Great cup to bring skiing. Just add hot water and a pack of hot cocoa or soup, and you are set! So much cheaper than spending $3.00 for a cup of cocoa.

    It works

    • Familiarity: I've put it through the wringer

    I'm a big fan of how it collapses, huge space saver, however that comes at a price. Anything you put in the mug WILL get stuck in the folds and crevices of the cup, so it's super hard to clean well in the backcountry. Also if you have hot drinks in there it'll be hot to hold. Other than those two things I haven't had a problem and its overall a pretty good mug, but you can find better mugs for less money.

    Dirt magnet

    • Familiarity: I've used it once or twice and have initial impressions

    I love the concept. In fact, I'm positively seduced by the all of the collapsible Sea to Summit X products - they're just COOL man!

    I have a hard time with silicone though. On paper, it's so bloody neat - temperature resistant and flexible, what's not to like?

    I'll tell you - if there's any dirt, dust, the smallest mote or particle in a 2-mile radius, it'll find its way onto your X Mug.

    This is not a Sea to Summit problem, this is a silicone problem. I have a set of Snow Peak Hot Lips, they're like pot holders for your face, a lip guard for your cup - anyway, they have the same issue.

    It doesn't take much effort to clean the Hot Lips, they're quite small. Cleaning off an entire mug would get old fast.

    On the other hand, it is pretty BAD ASS the way it collapses. Most of the X line nests together in some fashion so you can assemble a Russian Doll set of cookware and dishes, which would be pretty cool.

    Tastes like barbie dolls

    • Familiarity: I've used it several times

    Taking off 1 star from an otherwise incomparable collapsing mug. Silicon will always hold onto oils and is very difficult to get clean in the backcountry. I discovered this somewhere in the Cascades, with a cup of Willamette pinot smelling powerfully of bacon, coffeee and Dr. Bronner's Lavender Magic Soap. This cup had been thoroughly cleaned - the essential oils from the soap and other foods had attached to the silicon. The smell only went away when boiling the cup in clean water an oily white residue collected on top of the water.

    Lesson learned: don't use scented magic soap.

    Awesome Cup

    • Familiarity: I've put it through the wringer

    Great cup for backpacking & traveling with. Love that it collapses so I didn't have to take up valuable pack space or hang it outside my pack. Worked well for cocktails & coffee! The silicone tends to collect some dirt but I could use the extra minerals. Cheers!

    the only dish you need for backpacking

    • Familiarity: I've used it several times

    I carried this for backpacking 4 nights in the Smokies. It worked great! It was durable and just the right size and shape for meals and drinks, so you don't need a separate cup and bowl. It collapses really well, and is extremely handy.

    Breaks easily

      This cup withstodd over 1 use! I drank coffee with it in the morning, then stowed it collapsed. Upon extending it in the evening for a beer, the ring and upper portion split. Hopefully Sea to Summit cistomer service has me covered.

      Breaks easily


      • Familiarity: I've used it several times

      This is an great cup. You can actually hold it with hot coffee/tea. I like that it is not hard plastic. It might be harder to clean than plastic but not hard enough to not use again. I was afraid of being able to taste the silicone, but that worry was laid to rest the first time I drank my morning java. I would recommend this cup to anyone.

      Light and compact

      • Familiarity: I've used it several times

      Thanks to other reviews, I found out that the cup ran small, and ordered the mug instead. Even so, the mug itself is none too huge. I love its portability and lightness. However, in a dusty campsite, I found that the dirt clung more easily to the silicone than to other hard plastic collapsible models. I will still continue to use and enjoy.

      Sweet Mug

      • Familiarity: I've used it several times

      This mug is great for camping and backpacking, it's lightweight and super easy to store. I use them for tailgating too, it's a sweet gadget to show your buddies and it can hold coffee to keep you warm! I even use it to eat my cereal in the morning when I go camping. They are also SUPER easy to clean, which is great in my book.

      Light and Versatile

        Extremely packable and simple to use. A friend recommended it for lightweight backpacking who also enjoys gourmet cooking. Found out you can nest it on top of a JetBoil (put some water in Jetboil first) and use it as a double-boiler to make backcountry fondue!

        nicely sized cup

        Just used these rafting the middlefork of the salmon, and always kept one handy in my jacket pocket for whatever the beverage dujour might be, and one in the cooler for anyone who might swim up to the bar. A must have for any excursion.

        nicely sized cup

        Nice Mug

          I like this mug. It's compact and nests with the bowl. There is a plastic taste to the semi rigid ring around the lip of the mug. And the silicone is thin, so hot drinks have to be held by the ring around the lip or with a rag. But overall I like this mug.

          i need something collapsible to keep water warm on a small coffee mug warmer/hot plate . . . would this melt on the hot plate?

          Can you microwave your tea/coffee in this...

          Can you microwave your tea/coffee in this in your motel room the night before you leave on the trail?

          Is this offered as a set of four, or do...

          Is this offered as a set of four, or do you pay $11.90 per mug? The reason I ask is because the photo shows four colors, but the options gives you indicates that there is only "One Color." I thought maybe that's because these are sold as a set. Otherwise, you don't have a choice in color?

          Best Answer

          Nope, just one at a time. Typically the warehouse guys will just pull whatever color comes up first, but I've sometimes placed an order by phone and requested something specific. They try their best, but it doesn't always happen. As for the "one color"- it could be that one or the other is all they have in stock, or that it's the grab bag. In either case, worth a quick call to clarify.

          I love the X-Mug but mine has developed a...

          I love the X-Mug but mine has developed a small hole at one of the folds, so now it leaks. (No idea how it happened.) Any suggestions on how to repair it? Nothing seem to stick to the silicone. Or could it still be under warranty? There's no warranty info on the Sea to Summit website.

          Best Answer

          Yeah, call STS @ 303-440-8977. Ask them to replace it under warranty, since it's lifetime. The fact that it developed a hole directly on one of the folds is easily a matter of making the argument that it was due to material failure. Or, as Dean said, if you bought it here, BC will replace it unconditionally as well, maybe even faster.

          Is there a difference between the X Cup...

          Is there a difference between the X Cup and the X Mug? Volume and weight are listed as the same.

          Is the Sea To Summit X Mug marked with...

          Is the Sea To Summit X Mug marked with measurements? If so, at what intervals? Thanks!

          Can you put this in the microwave? I am...

          Can you put this in the microwave? I am liiking for something to make tea in after riding my bicycle to school.

          Yes, it's completely safe for microwave use. Silicone has a safe temp rating of 428F/220C and your usage will never be greater than 212F/100C. The Nylon lip has a temperature rating of anywhere from 390F/199C to 490F/254C depending on the type of nylon, but the ring would be insulated by the silicone, so it's not even an issue.

          without a handle...doesn't it get to hot...

          without a handle...doesn't it get to hot to hold coffee or soup?