Exact product photograph.A closer lookBottle accessories
Unscrew. Drink. Keep it simple.
Hydro Flask Wide Mouth Flex Cap
Black · screw-off cap
Buyer feedback ↓A closed cap with a flexible carry strap for Hydro Flask Wide Mouth bottles, without a drinking straw to clean.
- 2.7 inL/WOuter cap diameter; not a universal bottle-thread size.≈ 0.8 bank-card lengths
- 0.17 lbCap weightManufacturer specification≈ 15.4 nickels
- Wide MouthCompatible bottle familyNot Standard Mouth or a tumbler lid
Amazon US · Black · screw-off cap · Retailer link
THE QUICK TAKE
Is it right for you?
Buy this if you prefer a simple screw-off closure to a straw. There is no drinking tube to trim or brush, and the flexible strap makes the bottle easy to pick up. It is a useful replacement or alternate cap for a compatible Wide Mouth bottle.
Choose a straw or sipping cap if you want one-handed drinks without removing the lid. This cap must come off each time. It is also a specific Hydro Flask part: the outside diameter does not establish compatibility with another brand.
01 / BUYING NOTES
Before you buy.
Keep the seal clean.
The cap is dishwasher safe. Follow Hydro Flask’s cap-care instructions, remove residue around the seal and close it fully before carrying the bottle in a bag.
Hydro Flask specifications ↗ · Manufacturer accessory fit chart ↗ · Exact black cap listing ↗ · Hydro Flask Wide Mouth Flex Straw Cap details ↗ · Hydro Flask Wide Mouth details ↗ · OXO Water Bottle Cleaning Set details ↗
02 / AMAZON REVIEWS
The buyers’ view.
Owners describe a tight seal and easy cleaning, with one reporting no leaks when carrying the bottle in a bag after switching from a straw lid. That makes the simple closure appealing for carrying rather than sipping on the move. A replacement buyer raises a longer-term concern: their original cap’s rubber seal deteriorated after years of use, and they worry the replacement will do the same.
What buyers like
- quality56
- fit38
- functionality20
- replacement12
- ease of use9
Mixed feedback
- Leak resistance36
- Durability16
- seal13
The small numbers are review mentions. Topics and sentiment are from Amazon’s customer-review overview.
Amazon US · Checked . Ratings may include other colors and sizes.
View source ↗03 / REVIEWS & VIDEO
See it in use.
See how it works, then read the findings behind the buying advice.
What is the Best Hydro Flask Lid?
See how the original Flex Cap differs from straw, chug and sipping lids. The comparison concerns lid types; no cross-brand fit is implied.
Watch on YouTube ↗Video and written sources are labeled by creator and tested scope. Manufacturer demonstrations explain use; they are not independent tests. No in-house hands-on testing is claimed.
Read source summaries Product scope is labeled · key findings in bold
The maker lists a leakproof closed cap, movable strap pivots and dishwasher-safe care. These are fit and handling specifications, not an independently verified drop or leak test.
The comparison lays out several ways to drink from the same bottle family: removing a cap, sipping or using a straw. That is the useful choice here; a different drinking style brings different cleaning parts.
04 / COMPARE
Different priorities.
Choose the tradeoff that fits how you will use it.
Swipe to see every alternative →
THIS GUIDEHydro Flask Wide Mouth Flex CapBlack · screw-off cap |  ALTERNATIVEHydro Flask Wide Mouth Flex Straw CapBlack · two trim-to-fit straws | |
|---|---|---|
| Amazon price | $14.90 | $14.95 |
| Bottle fit | Hydro Flask Wide Mouth | Hydro Flask Wide Mouth |
| How you drink | Remove the entire cap; tilt bottle | Flip spout and sip upright |
| Main tradeoff | Simple closure; needs two hands to open | More small parts to clean; cold drinks only |
| Explore | Read buying guide →Source ↗ | Read buying guide →Amazon source ↗ |
About these everyday comparisons
Approximate comparisons to familiar objects: a bank card’s 3.37-inch long edge, a Letter sheet’s 11-inch long edge, or a US nickel’s 21.21 mm diameter / 5 g weight. Water comparisons exclude the container’s weight. Capacity comparisons describe volume, not exterior size or how food fits. Reference pictures identify the object; use the labeled ratio for the comparison.
05 / PRICE HISTORY
The price over time.
Hydro Flask Wide Mouth Flex Cap · Black · screw-off cap · Amazon US
The chart legend identifies Amazon and new-offer prices when available. New offers can include marketplace sellers. Coupons, shipping and size/color selections can change the final price. Blank periods are missing observations, not a zero price.
06 / RELATED FINDS
A few useful extras.
For the way you plan to use it.
Use an alternate cap on a compatible bottle.
Hydro Flask Wide Mouth
Our selected Wide Mouth bottle accepts this cap. It comes with a straw cap already, so this is an optional change in drinking style.
Clean the cap seal and bottle.
OXO Water Bottle Cleaning Set
The small detail brush reaches around the removable seal, while the larger brush cleans the bottle interior.