The Sennheiser EW-D SK Base Set (S1-7) is a digital wireless system without a microphone, for users who already own, or want to choose, their own lavalier, headset or instrument cable. It pairs the half-rack EW-D EM receiver with the metal-bodied EW-D SK bodypack, which takes a separately sold clip-on, headset or instrument cable via its locking 3.5 mm input. Sennheiser Evolution Wireless Digital (EW-D) is a digital UHF wireless system with 24-bit audio, a 134 dB input dynamic range that removes the need for gain adjustments, 1.9 ms latency and intermodulation-free equidistant channel spacing that allows up to 90 channels in 56 MHz of tuning bandwidth. Setup and monitoring are handled from a phone or tablet through the EW-D Smart Assist app over Bluetooth Low Energy, with auto scan to find clean frequencies. The EW-D SK bodypack has a metal housing and runs up to 8 hours on the two supplied AA batteries or up to 12 hours on the optional BA 70 rechargeable pack. This S1-7 variant covers 606.2 to 662 MHz. In the box: EM receiver, SK bodypack, two rod antennas, NT 12-5 CW power supply with country adapters, GA 3 rackmount set, four rubber feet and guides.