We have a video for every Shelter Shutter type and door type. There are Single Fold and Multi Fold Shelter Shutters, and the only significant difference in door types would be if your door has raised molding or not. If your door does NOT have raised molding, you do not need spacers. If your door DOES have raised molding, you need spacers. Spacers come in pairs, and 4 spacers are included with stock size shutters which will accomidate a door glass molding thickness of up to 3/8" thick. When you order custom shutters, the correct number of spacers will already be applied to the back of the shutter.