Cal Royal Full Mortise Hinge - Non Removable Pin - Satin Stainless Steel BB31-32DNRP

4.5 x 4.5 Full Mortise Hinge, Square Corner, 5 knuckle, .134 Gauge Stainless Steel, Ball Bearing for Standard Weight Doors, Non-Removable Pin, Satin Stainless Steel Finish

Classroom Lock Function: Lock operated by lever from either side except when outside lever is locked from outside by key. When outside lever is locked, latch bolt is operated by turning inside lever.