RCA female stereo inputs and outputs Frequency response from 20Hz to 20kHz; 0-15dB adjustable gain Size (LxWxH) 4.29" x 2.87" x 1.69" Input impedance 47K Ohms; Output impedance 100K Ohms 12V DC power (adapter included) Stereo Line-Level Boost Amplifier Based on the LM-833N op-amp circuit, these amplifiers provide up to 15dB of exceptionally quiet gain. Intended for line-level correction, whether you are dealing with a long wire-run, or just have a piece of equipment with a low output, these line-level preamps will give you just the boost you need.