Acoustically matched and treated backboxes allow Strategy Series speakers to perform with optimum resonance-free operation. Standard units include three, easy-toadjust clamps that rotate and secure with a screwdriver into ceilings up to 1 1/4" thick. They may also be installed by conventional screw mounting if desired. Models are offered in 4", 6" and 8" sizes in volume and economy versions. Volume Model Series FA97 and Economy Model Series FA95 are 22-gauge CRS, undercoated and equipped with four threaded speaker inserts and three grille-stud receptacles. Both are finished in black epoxy. FA97 Series is lined with 5/16" thick high-density acoustic batting for superior full-range music performance.