Timeless design, great finishes and top quality brass construction make this our most popular style of mail slot. The open back plate model is a good option for businesses or home locations where privacy is not a concern (such as a vestibule or closet). A larger opening size allows magazines and legal envelopes to slide through without folding. The external flap is spring loaded to keep it closed and reduce drafts.Dimensions. Exterior and interior face plates: 13" W x 3 3/4" H. Opening in plate: 11" W x 2 1/4" H.What is PVD finish?