C.R. LAURENCE 9412A CRL Satin Anodized 4-1/2" x 12" Package Drop Slot. CRL Aluminum Package Drops are a wider version of our Deluxe Mail Slots. They are preferred in facilities where larger parcels such as manuscripts, legal briefs, video tapes and discs are delivered. Designed to fit into glass doors or sidelites glazed with 1/4" (6 mm) glass. Concealed spring mechanism on flap keeps it closed securely, preventing infiltration of dirt, dust, and water. A turn latch on the flap allows for securing the flap at night, or when not in use. Package Drops are available in seven sizes and two popular finishes..