Acoustically tuned and treated back boxes allow the Strategy Series speakers to operate at optimum resonance-free performance. Standard units include three easy-to-adjust clamps that rotate and secure with a screwdriver on ceilings up to 1 1/4" thick. They can also be installed using conventional screw mounting if desired. Models are offered in 4", 6", and 8" sizes in both volume and economy versions. The FA97 Series volume models and the FA95 Series economy models are 22 gauge CRS, bottom-lined, and equipped with four threaded speaker inserts and three grille bolt receptacles. Both are finished in black epoxy. The FA97 Series is encased in 5/16" thick, high-density acoustic batts for superior full-range musical performance.