Ball knob style keyed classroom function lock with BumpStop® - commercial. Brushed chrome finish. For Classroom application - Either knob operates deadlocking latchbolt unless outside knob is locked by key. Inside knob is always active. Key unlocks outside knob. BumpStop® technology - Bump resistant cylinder. Cylindrical construction for enhanced durability. Six pin Schlage C compatible cylinder standard - Can be special ordered to 24 different keyways. 2-3/4 in fixed backset latch. 3 hr UL listing. Meets ANSI/BHMA A156.2, grade 2 standards. Box packaging, master carton quantity 8. Master Lock® Cylindrical Ball Knob, Commercial Grade, Series: BLC, Lockset Function: Classroom, Ball, Full Lip Square Corner Strike, 2-3/4 x 1-3/4 in Strike Dimension, Grade: 2, 2-3/4 in Backset, 6 Pins, 2 Keys, Alike Keying, Schlage SC4 Keyway, For Door Thickness: 1-3/8 or 1-3/4 in, Steel, Polished Chrome/Brushed