Check the listing for details. Entry Door Knobs with Key Stainless Steel Round Ball Lock 50mm(1-31/32") Backset. Color: black, Condition: New. Listed at 28.44 USD. APPLICATION:This interior door ball lock can be locked from the inside by pressing the button on the inside, or from the outside using a key. It is widely used in various residential, commercial and institutional doors such as apartment buildings, interior doors, bathrooms, kitchens, bedrooms, study rooms, office buildings, warehouses, etc.ADVANTAGES:The lock body is made of zinc alloy, the surface is multi-layer electroplating, brushed polishing process, rust-proof, corrosion-resistant, and non-fading.The lock tongue is made of thickened solid silent 304 stainless steel, which is smooth to open and close, effectively reducing the noise generated by opening and closing the door.PACKAGE CONTENT:Backset: 50 mm / 1-31/32 inchSuitable for Door Panel Thickness: 35-50 mm / 1.38-1.97 inchRound Door Lock Outer Diameter: 74 mm / 2.