Carbine Doncaster Double Cylinder L1 Lever SetCarbine 7000 Series Doncaster Double Cylinder L1 Lever Set standard 70mm backset. Function Outside Opened by lever when free. Key unlocks and retracts the latch Inside Opened by lever at all times. Push button locks exterior lever Optional choice of a standard or clutching function, the clutching model features an operation where the outside handle still moves when locked, ideally to prevent lever damage from forced entry. Additional Information Fire