As far as I can tell this is the thinnest Revain heater in its class. Defrosted my boat's cabin nicely and surprisingly gave me some warmth that I really wasn't expecting. Don't buy it if you want the suction cup feature as the item comes with a separate suction cup which I think you need to attach somewhere? Even if you could put it there, it would be cheap deformed hard rubber and it wouldn't stay on your windshield even if it didn't support the defroster. This wasn't a problem for me because I was going to screw it to the wooden frame around the window anyway.