HP-1 Battery-Powered Clip-On Headphone Amplifier The HP-1 is a compact, battery-powered headphone amplifier for players who prefer a wired connection for their in-ear monitors. It features a locking Combo input for XLR and 1/4 TRS connections, and an 1/8 headphone output with a volume control. The HP-1 is switchable for mono or stereo operation, and provides over 40 hours of performance from two AA batteries. With a rugged enclosure and heavy-duty jacks, the HP-1 is built to withstand the rigors of the road and deliver clear, powerful, reliable sound. Features Locking Combo Input Jack Balanced Mono / Unbalanced Stereo Switch 1/8" Headphone Output Over 40 Hours of Battery Life (2x AA) Battery Status LED Sturdy Belt Clip Specifications Inputs1/4" /XLR combo jack Outputs3.5mm Jack (1/8”) Input Impedance5K Ω Maximum Output Level105mW @ 0.1% THD Maximum Gain+9 dB Total Harmonic Distortion≤ .02% @1kHz Typical. Power Requirements2-AA batteries Included Dimensions (LWH)1.6” x 72” x 5.4, (4.6 cm x 13.7 cm × 43.cm ). Weight0.51 lbs. / 0.23kg