Sennheiser EW-D SK Y1-3 - Digital pocket transmitter for EW-D wireless systems, frequency range Y1-3: 1785,2–1799,8 MHz, transmit power: 12 mW, operation with 2x AA batteries or optional BA70 rechargeable battery, dimensions (WxHxD): 63 x 80 x 20 mm, weight: 120 g