Master lock 8239e criterion high security chain is a hardened steel chain with mini u bar it has 10mm octagonal links which deliver a strong cutting resistance a dual locking mechanism provides an additional level of security criterion locks are dedicated to all cycling enthusiasts in guaranteeing the highest level of protection against theft patented octagonal shackle is unique and patented the 8 sided extra thick shackle not only offers maximum resistance to cutting but also delivers signifi