The 3i-1711-SEN case fits the Sennheiser EW100, EW300, and EW500 Series Wireless Microphone Systems. The custom cut PE interior foam is designed to securely transport the entire Sennheiser EW Wireless Microphone package including the receiver, antennas, handheld mic transmitter, body pack transmitter, lavalier microphone, mic clip, power supply, spare AA batteries, and other additional accessories. This case will also fit the Sennheiser IEM transmitters and receivers.