Electronic Keyless Lock Function Classroom with Key Override Access Method Keypad Mounting Style Mortise Lock Material Zinc Alloy Finish Satin Chrome Series DL4500 Handle Type Lever Door Thickness 1-3/8 in to 1-7/8 in Key Override Options 1-3/8 in Mortise Cylinder Hand Left Power Source Battery Battery Life 60 000 Cycles Max User Codes 2000 Standards UL Listed Weather Resistant Yes Electrical Ligature Resistant No