The DKGL (DoorKing Gate Lock) series of magnetic locks are designed for outdoor gate applications.  Magnetic locks have no moving parts to wear out or break and are virtually indestructible. 1200 Lb locks are typically used for vehicular gate applications while the 600 Lb lock is used for pedestrian gate applications.   
 
This kit includes predrilled and tapped lock and armature mounting brackets that can be welded to the gate.  The magnetic lock and armature are then bolted to the brackets with the supplied hardware. 

The 1216-081 kit is the same as the 1216-080 kit plus the lock includes a built-in signal relay to indicate the status of the magnetic lock: secure or unsecured.