These spring loaded hand retractable plungers have a wide range of applications to lock items in place. They are used to prevent any change in position due to lateral force. Pulling up on the D-ring retracts the plunger pin completely into the body and unlocks the mechanism. The locking style allows the plunger to remain in the retracted position. The D-ring is made from 300-series stainless steel uncoated. The body and plunger pin are made from AISI-4140 alloy steel with a black oxide finish. The spring is made from 17-7 stainless steel.