Three point eight inches deep is thin enough that this cabinet can hang on a door without the door catching on a wardrobe or a wall, and the mirror still measures 11 x 39.8 in. Eight LED lights run on three AAA batteries, not supplied. The MDF frame is described as thick enough to resist warping over time, which is the usual failure point on thin hanging cabinets. Overall the panel is 14.6 x 43.3 in and it locks. Both wall and door mounting hardware are covered, and a white finish keeps it visually flat against a pale wall.