Abstract: A padlock is provided with a multi-layer protective metal shell having non-aligned, alternating seams among the various layers, primary and secondary key-operable locks attached to the shackle of the padlock by a drive linkage that will fail before the primary and secondary locks to maintain the integrity of the lock, an ergonomic shape, an offset shackle for facilitating use of the lock in close-quarters applications, and a modular cushioned bumper for attachment to the outside of the lock body that is color-coded to correspond to a key and includes a protective cover over the keyway accessing the lock cylinder which is moveable to facilitate insertion of the key into the padlock.