Features: The Electro-Voice HM3 Omnidirectional Headworn Microphone provides hands-free speech and vocal operation with the Electro-Voice R300 wireless microphone system. The HM3 connects to the BP300 beltpack transmitter. Specifications: Package Weight: 0.1 Lbs. Box Dimensions(LxWxH): 4.7 x 3.9 x 0.6" Model: HM3 Manufacturer: Electro Voice