From The Anvil BZP Maco Interlocking Stable Door Lock 45mm BS

Description

For use with 92mm centre espagnolette handle sets.
Chamfered locking hooks provide excellent weathersealing.
Integrated shootbolt interlocks top and bottom sashes together.
Maco easy latch reduces noise and the force required to latch the door and can be easily reversed.
BZP, or ‘Bright Zinc Plated’, products are made from steel and plated with a thin layer of zinc using an electric current, to protect against rusting and oxidisation.