RV-FS22SPB Sound-Panel 22mm Mounting Spacer - BlackThe Sound-Panel has three accessory mounting spacers available to create a professional indoor or outdoor install, where cavity depth prevents standard speaker installation.Simply select the spacer size that suits your installation mounting depth and start your install.Use the 22mm (7/8") spacer to create a clean indoor or outdoor installation of the RV-FS402W / RV-FS402B Sound-Panel when the minimum wall or ceiling cavity is 19mm (3/4").WARNING: This product can expose you to chemicals which are known to the State of California to cause cancer, birth defects or other reproductive harm. For more information go to P65Warnings.ca.gov.