The Kryptonite New York Standard U-lock has an 16 mm Max-Performance steel shackle. This makes it resistant to bolt cutting or lever attacks. This is additionally supported by the central Electronic-Key adapter. Closure system: Key lock Key: 3 Type: D lock Material: Steel Additional Information: - Hardened 18 mm MAX-Performance steel shackle resists bolt cutters and lever attacks - Patented double-walled locking bar made of hardened steel for maximum security - Double locking mechanism offers more protection against opening of the lock by twisting - Centrally positioned Electronic-Key adapter protects against lever attacks - Vinyl cover protects against damage - Rotatable dust cover protects the lock cylinder - 3 stainless steel keys - One key with LED light and replaceable battery Lock Barrel: High-security disk locking cylinder Weight: 1970 g Theft protection: Highest security Security Level: 9 Closure Type: Key lock U-Lock Size Dimensions Clamp Height: 203 mm Clamp Width: 102 mm Clamp Diameter: 16 mm