RockyMounts Compton Stainless Steel U-Lock SilverRockyMounts Compton Stainless Steel U-Lock was developed for maximum U-Lock security in urban environments of your most cherished possessions. The 18mm stainless steel shackle is the largest and toughest out there. It is RockyMounts toughest lock made from non-corrosive 304 stainless steel and carries a 10 out of 10 security level.815189020455