Reviewed By Carlos M (Los Angeles, CA) —3/5/2017 8:19 AM
I went with the large to be sure. Drill a deep enough pilot hole, the screws provided brake if you attempt use a drill with out a pilot hole. Also the little plastic spacer between the head of the screw and bar ten to snap as you drive the screw in, it almost hit me in the eye twice. If using a power drill drive it in slow and easy. The strap to secure the box is really nice, I might buy more of those.