This was placed on a metal door in a garage with a large window facing due west. The garage really heats up in the summer with all the sun coming in. I'd been dithering for a long time whether to buy this blind and then after we lost some shade trees after a storm, one afternoon's hot sun pouring in and turning the laundry area into a virtual sweatbox was all it took for me to order one of these and put it up as soon as it was delivered. It's great! It took just a few minutes to snap the blind together and position it on the door. It's nice looking and fits the door and window perfectly. The magnets at the top which hold the blind in place are very strong. The bottom magnets keep it from swinging around as the door moves but are not so strong that the blind can't be easily raised. Best of all, the garage is noticeably cooler and more comfortable in the afternoon.