Mounting spacers for the RV-FS402 sound panels create a professional indoor or outdoor install, where cavity depth is too shallow for speaker installation. Select the spacer size that suits your installation mounting depth. Model RV-FS41SPW Description Spacer Size 41 mm Color White 16 mm Spacer: Use when the minimum wall or ceiling cavity is 25mm (1")
22 mm Spacer: Use when the minimum wall or ceiling cavity is 19mm (3/4")
41 mm Spacer: Use in a surface mount installation