The Williams Sound WIR SYS 7518 features the WIR TX75 infrared transmitter ensuring members in a conference room, courtroom, classroom, or various other mid-sized venue receive direct and clear communication of your message without sacrificing security. The kit include a comfortable stethoset-style, WIR RX18 infrared receivers that are ideal for single or two-channel applications. The particular sleek and stylish TX75 with TX75-S slave emitter is designed to maximize coverage area with as much as 4,000 square feet in single-channel function. Purchase additional slave emitters for coverage all the way to 2,000 square feet for total coverage of up to 6,000 square feet. Placing more slaves within the same room increases coverage and increases freedom of movement. A single CAT-5 cable carries both power and signal to slaves for a truly one-cable connection.