Frameless Stainless Steel Mirror with Masonite Back shall be fabricated of 18-8 stainless steel, type 304, No 20 gauge with No8 mirror finish. Backing shall be 1/4" (6mm) thick tempered water resistant Masonite. Unit shall have 5/16" (8mm) returns to wall all around. Unit shall be provided with four (4) 7/32" (5.5mm) dia. mounting holes.