Sennheiser EW-D SKM-S (R4-9)

The EW-D SKM-S is the handheld transmitter of the digital Evolution Wireless range. It works in UHF with 2,240 tunable frequencies across 56 MHz of bandwidth, so up to 90 channels can run in one band without getting in each other's way. A 134 dB dynamic range means there is no input sensitivity to set on the transmitter — and when it is needed, the gain can be trimmed remotely from the Smart Assist app. A BA 70 battery lasts 12 hours, AA cells eight.