SDC HiShear is a high security, failsafe locking mechanism with superior appearance. The patented HiShear electromagnetic lock design incorporates a "floating" armature assembly and special alloy steel locking "tabs" on both the lock and armature assemblies, that may be adjusted both vertically and laterally to compensate for wide door gaps and warped or misaligned doors. HiShear magnetic locks are ideal for use on commercial grade hollow metal and wood doors and metal frames and Herculite doors with top rails.