Acoustically matched and treated backboxes allow Strategy Series loudspeakers 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 loudspeaker 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.