Made of Stainless Steel 19mm diameter dropbolt and moves 140mm Bolt On For double swing gates The Gatemaster stainless steel locking dropbolt is a bolt on stainless steel drop bolt which is lowered and rotated so that the lifting plate folds across the edge of the first gate. It is consequently locked in position and as a result, closing the second gate prevents the drop-bolt from being unlocked. The second gate can now be locked to the first gate with a standard gate lock and the gates cannot be spread apart because the drop-bolt is locked in position.