A lock includes a plurality of elongated buttons, each of which has on the sides thereof a plurality of gates spaced angularly and longitudinally from one another. A case contains the lock and defines a plurality of bores within which the buttons travel. The buttons are urged out a front cover of the case by biasing springs and are normally prevented from rotation by engagement with keying protrusions on the case. The lock includes a locking bolt which is coupled to a checker plate. The checker plate defines a plurality of edges that engage the sides of the buttons and are received in the gates therein only if the buttons are properly positioned.