The HDR 175 Headset for RS 175 System from Sennheiser can be used as a replacement or secondary headset with their RS 175 wireless system.
Earpiece Design: Over-Ear (Circumaural), Closed-Back
Driver Type: Dynamic
Frequency Response: 17 Hz to 22 kHz
Maximum Sound Pressure Level (SPL): 114 dB at 1 kHz
Total Harmonic Distortion (THD): 0.5%
Runtime: 18 Hours
Weight: 11 oz / 310 g (with Batteries)
Package Weight: 1.5 lb
Box Dimensions (LxWxH): 8.8 x 8.2 x 4.9"