from 6.99

The capCAP was humangear's first product, and its popularity has increased every year since we launched it in 2008. Now, after eight years on the market, we've gone back to the drawing board in order to add more compatibility and functionality with stainless steel wide mouth bottles.

Speaking of stainless steel, you might want to checkout our newest product: casq

As always, the capCAP is 100% BPA-free, polycarbonate-free, and phthalate-free, and both caps are made with FDA-approved, food-safe polypropylene (#5) plastic.

We're as disappointed as you that the capCAP has been out of stock for so long. We are working on some design updates to improve the usability of the new capCAP and look forward to releasing it this winter. We'll be notifying our mailing list when capCAPs are back in stock. 


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The water bottle cap for humans.


capCAP Travel 3.jpg

capCAP is the civilized 2-in-1 accessory cap designed to work with Nalgene, CamelBak, and other popular wide-mouth drink bottles. The new, re-designed capCAP is also compatible with HydroFlask, casq, and similar wide-mouth bottles.* The capCAP-Mason works with all glass jars that have "regular mouth," standard mason threads.

Most wide-mouth bottles are easy to fill and clean, but the standard opening is too big to drink from without spilling. Narrow-mouth bottles are great to drink from but you can forget about putting ice cubes in them, let alone cleaning them. And bottle inserts don't really fix a spout that was never meant for daily drinking.

capCAP offers the best of both worlds. Drink spill-free through the small spout, and then clean and fill easily with the large cap. The rubberized caps (available in green, blue, or black) are easy to grip, even with gloves on. Don't forget that the wide, rounded strap is more comfortable to hold too.

The new capCAP has a few additional cool features like the "CapKeeper" that holds the small cap out of the way when drinking and rubberized grips on BOTH small and big caps.

capCAP is 100% BPA-free, polycarbonate-free, and phthalate-free. Both caps are made with FDA-approved, food-safe polypropylene (#5) plastic. It is also covered by our lifetime warranty.



Green / Gray
Blue / Gray
Black / Gray
capCAP-Mason only comes in Black/Gray

Opening Size: 2.5" (63mm)

Dry Weight: 1.4 oz. (39.7g)

Cleaning: Dishwasher-safe (top rack only)




Is the capCAP compatible with stainless steel bottles? 
The newest version of the capCAP is compatible with stainless steel bottles thanks to some upgrades we made to the seal in the large cap. The original version of the capCAP was not designed to work with stainless steel bottles and is not compatible.

How do I know if the capCAP I'm going to buy is the newest version?
The newest version of the capCAP is the "capCAP+" and it will be available in late 2017. The capCAP+ differs from the original capCAP in the following ways:
-capCAP + features a "CapKeeperTM" feature on the strap that allows you to temporarily hold the small cap to the strap so its out of the way when drinking.
-capCAP+ features silicone gaskets on both the small and large caps.
-capCAP+ features more angular grip features on both the small and large caps that are easier to grab and hold than the original, rounded grip cutouts on the capCAP.
-capCAP+ has modified threads that allow it to seal on insulated stainless steel botlles like the humangear casq and HydroFlask bottles. See the "Cmopatibility" section below for more information. 

What other water bottles are capCAPs compatible with?
capCAP works with most popular BPA-free wide-mouth bottles. If you refer to the capCAP compatibility information below (in the compatibility section), you will find more specific information on compatibility. Please note that there are too many bottles on the market for us to know all of the ones that are compatible. So if you discover a new compatible bottle, please let us know. We will add it to the site.

Why does leaking occur between my water bottle and the capCAP?
If leaking occurs, you are likely using a water bottle that is not compatible with the capCAP. Please refer to the capCAP compatibility information below.

What are the thread dimensions of the top cap?
The smaller cap (or top cap) is non-standard and was designed to work solely with the capCAP.

Where's the most interesting place that humangear has had a meeting?
There have been some pretty epic meeting locations, but we'll have to go with the inside of a Toyota Chinook overlooking San Francisco from the vista point at Twin Peaks.

What are the care and cleaning instructions for the capCAP?
The capCAP should be washed before first use. To clean, hand wash in warm soapy water. If your capCAP begins to have an odor, we have a number of other suggestions including soaking it in warm water with lemon; soaking it in warm water with baking soda; washing it in a dishwasher away from the heating element (be sure to remove the strap first as the strap isn't dishwasher safe) or follow some of the recommendations for cleaning Nalgene bottles.

I purchased a capCAP between November 2016 and February 2017 (this capCAP has a gasket on the large cap and the CapKeeper feature). Was this version of the capCAP recalled?
Yes. For more information on the version of the capCAP that was recalled and to determine if you have a recalled capCAP, please visit the Recall Information page of our website. Please note that the the newest version of the capCAP (called "capCAP +" -- not yet available) will also have a gasket on the large cap and the CapKeeper; however, capCAP + will also have a gasket on the small cap and the exterior material of its large cap will *not* be rubber.




The newest (2017) capCAP works with even more “wide-mouth” (63mm-opening) water bottles than the original capCAP. The new version works with all of the original bottles (below) as well as wide-mouth stainless steel bottles like the humangear casq (20oz), HydroFlask wide-mouth insulated SS bottles, Nalgene SS (single walled), and Guyot SS (singled walled). The newest capCAP is *not* compatible with Klean Kanteen wide-mouth insulated SS bottles or CamelBak insulated SS bottles. While it is possible that the new capCAP may work with other bottles that have similar 63mm openings, we do not claim compatibility with any other bottles not listed here.

The capCAP-Mason (2017) works with all glass jars that have "regular mouth," standard mason threads.

The original capCAP (2008 - 2016) works with many popular 63mm wide-mouth bottles including: Nalgene 1L (HDPE, Everyday, PC), Nalgene 48oz “Silo” bottles (HDPE, Everyday), Nalgene SS, Guyot SS, Nalgene OTG (Everyday, PC), all CamelBak Better Bottles, CamelBak Chute and Eddy bottles, and Cyclone (PC). The original capCAP is *not* compatible with HydroFlask and Klean Kanteen wide-mouth bottles. Some customers have nonetheless tried the original capCAP on the Klean Kanteen and HydroFlask bottles and have reported mixed results i.e. we’re told they work on some of those bottles but leak on others. Despite these mixed results, we stress that the original capCAP was *not* designed to work on either the Klean Kanteen or HydroFlask bottles and we do not recommend use on those bottles. The original capCAP is not compatible with the 16 oz. Nalgene bottle either.

* TRADEMARK INFORMATION: All trademarks, trade names, and logos mentioned or illustrated are the property of their respective owners. Reference to, or illustration of, any commercial products that the capCAP is compatible with does not constitute or imply endorsement, recommendation, or favoring of the capCAP by their respective manufacturers.