5 lever locks are a more secure option than the 3 lever version. The locks have 500 key patterns - at least 500 different key patterns must be made before any key pattern can be used again.
Mortice sashlock 2½" Electro Brass LAL0003
Mortice sashlock 2½" Satin Chrome Plated LAL0033
Mortice sashlock 3" Satin Chrome Plated LAL0086
For external use
Hardened steel rollers
False notching to prevent picking
2 keys supplied