Security U Lock. ø 18 mm passivated hardened steel shackle. Shackle protection cover in black matte finish. Hardened steel lock body. Hardened steel double bolt locking mechanism. 7 discs high security lock cylinder. Sawing and attack proof, pick proof cylinder. Shackle anti-rotation feature in case of cutting. ABS end caps and key dirt cover. 3 flat milled keys. Key cutting service, using exclusive copy code. SRA certified.