UBP800 Body-Pack w/Lavaliere Microphone Audio mute switch allows convenient audio muting while leaving the transmitter "ON" LED indicator: Unit "ON", and "Low Battery Alert" Locking 3.5mm mini-jack provides secure connection for removable microphone Convenient, economical operation with AAA alkaline or NiMH batteries (2x) 2-1/4" W x 3-3/8" H x 1" D; antenna 3-3/4"; 2.8 oz. (without batteries) Lavaliere Mic: 4 ft. long cord; 0.6 oz. UDR800 800-Channel PLL-Synthesized UHF Receiver Offers 800 user-selectable frequencies in UHF 470-490 MHz band; 120 dB dynamic range; operation up to 500 feet line-of-sight DigiTRU Diversity for maximum range and dropout protection, full LED indicators, 1/4" unbalanced and XLR balanced outputs, Tone Squelch for locking out potential interference, noiseless transmitter ON/OFF switching, & level control for unbalanced output Half-rack receiver design with front panel dual antennas, powered by wall power adapter 8" W x 1-5/8" H x 5-1/8" D; antenna 2-3/4"; 1 lb.