Professional UHF Dual Wireless Instrument Microphone for Saxophone Clarinet Tuba Trumpet.This wireless system is super professional wireless microphone system at an unbeatable price. Its full featured design with diversity operation, 100 selectable channels, Tone Lock Squelch circuit, automatic transmitter setup, and up to 20 units can work at the same time without interference, which satisfies professional use for Sax and other musical equipments.