These Square key locking zinc alloy double hung sash locks are designed to mount on the inside center top edge, and when engaged will prevent the window from opening, these will with all your other traditional hardware.
This fitting is suitable when you want to secure windows with a key.
Kit includes sash fastener with locking plate 4 x fixing screws
Six Different Finishes Available
Suitable for Residential Timber Sash Windows
Finishes: Polished Brass, Antique Brass, Antique Copper, Matt Black, Chrome plate, Satin Chrome,