Check out Sony WRT-8B, an UHF synthesized body-pack transmitter with a compact and rugged design. Widely used in interviews, entertainment shows and conferences, users will be extremely pleased with its long alkaline battery life, wide frequency bands and packaged with Sony's lavalier microphone. Ultra stable and programmable operating frequency programming Secure audio transmission by pilot tone Rugged magnesium chassis is able to withstand years of usage "on the road" Supplied with protective case Battery alarm Specification | Detail | Oscillator | Crystal-controlled PLL Synthesizer | Type of Emission | 110KF3E | Carrier Frequencies | 792MHz to 806MHz | RF Power Output | 50 mW / 10 mW (selectable) | Frequency Response | 40 Hz - 20 kHz | Antenna | 1/4 ? wavelength wire (SMA-J type connector) | Pilot Tone Signal | 32kHz | Reference Deviation | MIC: +-5kHz (-60 dBV, 1kHz input) LINE: +-5kHz (-20 dBu, 1kHz input) | S/N Ratio | 60 dB or more (+-5kHz deviation at 1kHz modulation, A-weighted) | Microphone Capsule | See Optional Accessories | Audio attenuator adjustment range | 0-40 dB (continuous) | Audio input level | MIC:-2 dBV (at 1kHz input) maximum LINE: +38 dBu (at 1kHz input) maximum | Audio input connector | Sony SMC9-4S type | Power requirements | DC 3.0 V (two LR6/AA size alkaline batteries) | Battery life | Approx. 6/13 hours with Sony AA-size alkaline (LR6) batteries at 25 degrees Celsius(77 degrees Fahrenheit ) at 50/10 mW respectively. | Dimensions (W x H x D) | 63 x 83 x 17 mm (2 1/2 x 3 3/8 x 11/16 inches) | Mass | 140g (4.9oz) including batteries | |