The Snap-N-Strut Wall Spacer is used between a wall and strut to reduce corrosion and improve the ability to clean behind the strut. In cases where a fixing bolt or screw is needed, the Wall Spacer can also be used to provide the necessary gap for the bolt head. THe standard Snap-N-Strut Wall Spacer has a 3/8 16 threaded hole in the center but it can be ordered with 1/4 20 thread or various drilled holes.