As part of your Evolution Wireless Digital microphone system, the Sennheiser SKM-S handheld wireless transmitter provides a rock-solid wireless foundation for all your favorite sonic signatures. Just pop on your existing Sennheiser or compatible third-party mic capsule (not included), sync to your EW-D receiver (also not included), and you’re ready to rock ’n’ roll. The SKM-S’s spacious, ergonomic design allows plenty of real estate for handheld and stand-mounted operation. One feature Sweetwater sound engineers are quick to note is the SKM-S’s foolproof on/off switch, which is as intuitive as we’ve seen in a wireless system. A pair of AA batteries gives users up to eight hours of wireless operation. Want to go green and save some green in the process? Connect the optional Sennheiser BA-70 rechargeable lithium-ion battery pack (not included) and get up to 12 hours of performance on a single charge.