The dimensions of the box are 6”wide x 6”deep x 7"high in the inside. Slot size is 3”long x 3/8”wide. This box has a 6.5”wide x 7.5”high sign holder on the front, hinged lid with a hasp and padlock.It can be wall mounted or set on a counter. Colored boxes still have a clear front where the sign inserts. Options – no sign holder, no lock, and add a pocket.