Mortise lock with 100% stainless steel mechanism. This model is specially designed for wood gates. The adjustable latch bolt in combination with the stainless steel hook (dead bolt) provides extra security. The combination of the hook (dead bolt) with the SHKW keep provides a secure anchoring of your gate while preventing the gate from being pried open as the dead bolt's "hook" locks into the keep's anchoring plate. The latch gap required is keep dependent, but the SHKW Hybrid keep requires a 7/8" latch gap.