A steel frame around the glass with an MDF backboard is what stops a bathroom mirror warping in humidity, where a frameless pane eventually clouds at the edges. The glass is shatter resistant with rounded corners, and the layered build holds it flat rather than distorting a reflection. It measures 36 x 24 in and 2 in deep, hanging portrait or landscape above a basin or a vanity unit. Black frame, 21 lbs. Fixings hold it square to the wall. This is the medium size option in the listing.