Key-in-knob/lever cylinders that have a single, capped pin chamber design are less efficient to rekey and service than key-in-knob/lever cylinders that have a slideable, removable spring cover. With a removable spring cover, pin segments can be loaded through the top of the cylinder versus using a plug follower. A slideable, removable spring cover makes rekeying or servicing the cylinder easier.

Language to use in key system specification:
The manufacturer’s non-interchangeable key-in-knob/lever cylinders shall be so constructed to use a sliding spring cover, not staked covers or caps, to cover each individual pin chamber.