The Union 21EU StrongBOLT Euro Profile Deadlock is ideal for timber doors hinged on the left or right and they are suitable for doors up to 54mm thick. The 14mm deadbolt is locked or unlocked by the key from either side, and gives a secure positive deadlocking. The 21EU deadlock has hardened steel pins that provide resistance against attack from sawing. The chamfered bolt design increases the performance of the lock under side load testing. The radius plastic splinter guard allows ease of installation. The deadbolt can be installed into many UK mortices without the need for additional carpentry or spoiling the edge of the door. Striking Plate: Finished to match forend.Face Plate: Supplied with square face plate which covers a radius inner forend.Case: Steel, red powder coated.Deadbolt: Brass with hardened steel rollers.Rebate Kit: 2100REB 13mm or 26mm. Forend: Brass finish.Case Size: 81mm x 89mm (3in).Backset: 57mm. This is the measurement from the edge of the door to the centre of the keyhole.