Kryptonite Keeper 12 Standard Heavy Duty Bicycle U-Lock with Bracket
- 12 mm hardened steel shackle, vinyl covered
- 4 x 8 inch U-lock inside size
- Key unlock, disc cylinder
- Click-style transport bracket included
Last refreshed Oct 3, 2026 · Based on the Amazon listing and published specifications, not hands-on testing.
A key-operated U-lock with a hardened shackle and a bracket for carrying it on the bike. The listing gives no formal security rating.
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ASIN: B000BL1P3OModel: 997955Category: U-Locks
Overview
A bike rack outside a shop, school or office is where a U-lock like this one gets used. The hardened steel shackle is wrapped in vinyl to protect the paint, and the lock opens with a key.
A bent foot design and a bracket that clicks onto the frame make this easy to carry and lock up quickly. The listing names the shackle size and disc cylinder but no independent security rating.
Who it's for
A commuter or student who parks a bike at racks and wants a conventional shackle lock with its own mount. Riders locking in areas with heavy theft should look for a lock with a stated security rating.
Pros and cons
- Hardened steel shackle resists hand tools
- Vinyl cover protects bike finish
- Bracket included for carrying
- Disc cylinder with collar over keyway
- Security rating not listed
- Key unlock only
- Fixed shackle size
Performance notes
The hardened shackle resists hand tools, and the reinforced collar over the keyway guards the weakest point of a U-lock. The bent foot design helps the shackle seat in the body, and the vinyl cover only protects paint, not strength.
Where it stands among u-locks
- #4 most-searched brand and model of the 8 u-locks lines we track (by search demand, not sales).
From the specs of the 15 u-locks we list; not a test result.
Specifications
| Brand | Kryptonite |
|---|---|
| Model | 997955 |
| Dimensions & fit | |
| Shackle | 12 mm hardened steel |
| Inside size | 4 x 8 inches |
| Construction & materials | |
| Material Type | Hardened steel, vinyl covered |
| Color | Black |
| Included components | |
| Included Components | Lock and click-style bracket |
| Other details | |
| Lock Type | U-lock |
| Additional Features | Key unlock, disc cylinder |
| Style Name | U-lock with bracket |
Frequently asked questions
Is the Kryptonite Keeper 12 a cable or chain lock?
No. It is a rigid U-shaped lock with a hardened steel shackle, not a flexible cable or chain.
Does the Kryptonite Keeper 12 come with a mount?
Yes. The listing says it includes a click-style transportation bracket for carrying the lock on a bike.
Does the Kryptonite Keeper 12 open with a code or a key?
It opens with a key. The listing describes a disc cylinder with a reinforced collar over the keyway, and mentions a Key Safe Program.