SLX-D Digital Wireless Combo Microphone System, includes one SLXD4 Receiver with 19" rack mount kit, one SLXD2 Handheld Transmitter with SM58 Microphone Cartridge (dynamic, cardioid) and one SLXD1 Bodypack Transmitter with WL185m Cardioid Lavalier Microphone, frequency band H55 (514-558MHz)