Dorex TL70 B C32D Medium-Duty Classroom Knob – Stainless SteelTL70 B C32D Classroom function suitable for doors that need to remain locked or unlocked for lengthy or specific periods Architectural quality for medium duty commercial applications High quality stainless steel finish For 1 3 8 to 1 3 4 door thickness 2 3 4 backset Optional backsets by special order: 2 3 8, 3 3 4, 5 Non handed field reversible Knob diameter is approximately 2 1 8 3 rosette diameter 1 2 stainless steel latch throw Concealed mounting