Engineered for applications with lim¬ited plenum space incorporating a Sound¬Tube-specific shallow backcan with an installed depth of only 3.5inches. One 4inch (102mm) treated fiber woofer with cloth surround and one 0.75inch (19mm) silk dome tweeter. Easy-access six-position tap switch for 25/70.7/100-volt and 16ohm transformer bypass position allows for easy ordering, stocking and installation. Reduced amplification costs with maxi¬mum efficiency including 87.5dB sensitiv¬ity and 16ohm impedance. Superior voice intelligibility with an average coverage angle of 100° (2–10kHz, independently verified). Cost-effective 16ohm settings allows for the use of multiples of two, four, or six speakers in a system using a standard amplifier without a transformer. Incorporates a painted steel grille for lasting durability. Ceramic input terminal accepts up to 10gauge plenum rated signal wire and includes thermal fuse.