Our CRL Night Service Window is of the kind frequently used for motel registration or 24 hour service station windows. The 16 gauge stainless steel housing is glazed with 1-1/4" (32 mm) bullet resistant acrylic. This is mounted on a 16 gauge stainless steel shelf that measures 14-3/16" (360 mm) wide x 18" (457 mm) deep x 2" (51 mm) thick. The shelf has a Non-Ricochet Bullet Resistant Tray for passing cash, credit cards, keys, etc. The entire unit slides into a wall opening roughly 14-3/4" (375 mm) wide x 20" (508 mm) high. The flange surrounding the wall opening is 2" (51 mm) wide. Custom size units are available to suit your needs. The Standard unit does not have a speak-thru. Voice transmission is via the cash tray. An overhang is recommended for exterior use.