A The DL2700 or T2 Trilogy battery operated lock was introduced in 1994. It featured 17 total user codes, a passage mode and was simple to program/change PIN codes. We made the lock housing large enough to retrofit over the mechanical PB lock. This easy retrofit installation opened a lot of opportunities for us. As endusers, we were looking for more features, a better quality product and easy to change handing and PIN codes.