Tell Light-Duty Commercial Ball Privacy Knob KT2176 . Light-duty commercial privacy ball knob. Satin stainless steel US32D . Performance Complies with ANSI A156.2, Series 4000, Grade 2, 400,000 cycles . UL listed for 3 hour fire door. Door range 1-3/8 to 1-3/4 . Backset Adjustable 2-3/8 to 2-3/4 standard. Strike T strike 1-1/8 x 2-3/4 standard. Tubular construction. Latch bolt operated by knob from either side. Outside knob locked by push-button on interior. Unlocked by emergency release on exterior or rotating interior knob. Finish Satin Stainless Steel, Latch Adjustable, Backset 2-3/8 In. or 2-3/4 In., Exterior Access Emergency Release, Interior Action Push-button, Security Level Grade 2, Strike T-Strike, Pkg Qty 1, Package Type Clamshell