The wireless handheld microphone with RF band M915 (902 to 928MHz). Available in cardioid microphone polar pattern. Features 1, 10, 25 or 50mW user selectable RF output, 60 to 15kHz frequency response and above 57dB at 1kHz (1Pa) 'A' weighted signal to noise ratio. With internal antenna, USB or battery power. Standard AA size four rechargeable NiMH battery included. 4-hour battery charge time and 8-hour continuous usage per charge, typical at 1mW battery talk time.