The LP1000 Series lock is a fully mechanical pushbutton access control with no electrical wiring, electronics, or batteries. This lock is designed to operate surface mounted exit devices (not supplied) from the outside using a tailpiece, replacing the key cylinder on new or existing devices. Exterior access is by combination. Egress is by interior exit device and is free at all times. The LP1000 lock meets Americans with Disabilities Act (ADA) standards. The lock can be used with many leading brands of surface-mounted (rim-mounted) exit devices; however, the LP1000 cannot be used with mortise design or most vertical rod exit devices. The exit device can be “dogged” open without affecting the operation of the lock. Designed for high-frequency use and indoor or outdoor applications. The pushbutton design eliminates problems associated with the issue, control, and collection of keys and magnetic cards. The combination can be quickly and easily changed to ensure continued maximum security once employees, tenants, or guests leave, saving the cost of new keys, key cylinders, magnetic cards, and card-encoding devices. Combination can be changed without removing lock from the door.