Kaba Simplex 900 Series Metal Mechanical Pushbutton Auxiliary Lock with Thumbturn, Fits 44mm to 54mm Thick Door, 16mm Deadlocking Spring Latch, Flat Front, Satin Chrome Finish Fully mechanical lock eliminates the material and labor expense of battery replacements Single access codeone easy to manage code for all users Lock is easily programmed via keypad without removing lock from the door All metal cast front housing, force-proof, clutch-protected thumbturn, metal exterior trim plate Field Reversible for Right Hand and Left Hand Doors