From The Anvil Black 5 Lever Sash Lock British Standard

From The Anvil Black 5 Lever Sash Lock British Standard

91055 (18234) 2.5 inches Case, 44mm Backset
91064 (18249) 3 inches  Case, 56mm Backset

The backset is the distance from the edge of the door to the spindle.

Complies with British standard . Patented easy latch reversal system and simple spring strength adjustment.
20mm solid steel anti-thurst, anti-saw, anti-drill bolt throw. It comes with a stainless steel box striker and all the necessary fixing screws.

Sizes:

ANV-91055 (was 18234)
Case Depth: 64mm
Backset: 44mm
Case Height: 112mm
Centres: 57mm
Forend Length: 166mm
Forend Width: 26mm

or

ANV-91064 (was 18249)
Case Depth: 76mm
Backset: 56mm
Case Height: 112mm
Centres: 57mm
Forend Length: 166mm
Forend Width: 26mm

These are also available as keyed alike which means that one key will operate all the locks.

ANV-91065 (was 18282) – same as  91055 (18234) but keyed alike.

ANV-91066 (was 18283) – same as 91064 (18249) but keyed alike

91059 (was 18239/BLK) Rebate Kit for use with the lock above, required when fitting a pair of door one closing onto the other ie. french doors – sold separately.