Hydro Flask Standard Mouth Loop Cap - Standard Mouth

Select Color: Banana Yellow
Quantity: 1



Select Color: Banana Yellow
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Need a replacement lid for your 12 oz or 21 oz Hydro Flask? We have you covered. The Standard Mouth Loop Cap is a leak-proof, vented cap that allows hot vapors to escape while closing the lid, ensuring a smooth and easy seal.

Perfect for everyday use, as well as the rigors of the outdoors, our caps aide in keeping your Hydro Flask contents hot or cold. The loop allows you to clip to a backpack or messenger bag and ensures your Hydro Flask stays with you wherever your adventure takes you.

The Standard Mouth Loop Cap is now available in new colors, too, as part of the Hydro Splash Line! Hydro Splash colors include Electric Blue, Banana Yellow, Limeade and Perfect Purple.

Our patent-pending loop caps are made from polypropylene PP#5 and are BPA-free.

Posted by Daks on 11/29/2014

1 Star Rating


this came with my 21 oz bottle and for over a year I've been raving about hydro flask but I guess when I put the bottle in the sink to wash some dishwater got inside the cap (I could hear it swishing around) Made some hot chocolate and went to work. Opened up the bottle and I guess the pressure from the hot chocolate released the hounds because I was greeted with the most rank, horrific nasty butt-juice garbage mixed with rotted food smell. The cap then proceeded to drip said butt-water on my hands which I sprayed with industrial-strength window cleaner. You better believe that the magic death dishwater stank outstank ammonia. I had to cover my hands in scented hand sanitizer to get rid of it. Meanwhile I had to poke holes in the lid to drain the rest of the butt juice chamber. But the damage was done. The plastic and washer absorbed the bootyhole toxins. Save yourself this terror and buy the metal cap if you put anything but water in this thing.

Posted by jenn on 08/23/2014

1 Star Rating

Std plastic cap fills with liquid if submersed

I have 4 other hydroflasks - all wide mouth. This is the first standard mouth I bought with a different cap. I soaked the bottle and cap in water after buying and now this cap is filled with water that leaks all over the place. So the content IN the bottle are fine but the cap itself has water in it :(

Posted by Anna on 09/24/2013

5 Star Rating

It's just exactly like the stopper that came with my standard mouth hydroflask,

Which is what I wanted: an extra stopper to make it easier to find one when I'm in a hurry and just want to seal my flask so I can get out the door. If you lose your stoppers often you may want to buy an extra or two as well!

Posted by betty patterson on 09/24/2013

5 Star Rating

Extra hydro-flask caps

Great to have extra caps for your bottles. If one is misplaced can still use your bottles.The bottles are great to take ever where, without the caps one can not keep their fluids hot or cold.

Posted by george on 09/24/2013

5 Star Rating

who knew

it exactly fits my standard mouth flask. where the original cap went is currently unknown. as long as this one doesn't get that email I'm happy.

Posted by Samantha B on 09/05/2013

5 Star Rating

With the pour spout

I didn't know if the pour spout would work all that well as they don't really advertise the vents as even being a pour spout, but they do work fairly well to pour coffee.

Posted by Barbra Q. on 12/27/2010

5 Star Rating


I'm still amazed when I burn my lips at the end of a day at the mountain. This is a product that I have now purchased for my entire family for Christmas, and they all agree, hydroflask's are the best water bottle that money can buy.