The ultimate chain for all round bicycle security the innovative abus city chain x plus lock is built around a nigh on impenetrable multi layered hardened steel lock body with powercell technology and the marvellous x plus locking mechanism its most definitely a trustworthy lock hexagonal section 10mm hardened steel chain includes a powerlink which fits directly into the lock body for extreme resistance to torque pulling attack an amazing sold secure gold rated lock and abus rated level 15