Audio All Pass Filter/Phase Rotator. This item has been assembled, and electrical test passed. Power Supply: +/- 5VDC to +/- 18VDC ( < 200mA ). Recommend best +/- 15VDC. Input Impedance: 5.5k OHM ( at 1kHz Sine wave ). Input Level: 2000mV RMS ( at Power supply +/- 9VDC). 2500mV RMS ( at Power supply +/- 12VDC). 3000mV RMS ( at Power supply +/- 15VDC). Frequency Response: 10Hz - 100kHz ( -3dB ). Module Size: 2" x 3" (50mm x 100mm), Max. height: 0.63" (16mm). Datasheet: https://www.czh-labs.com/tmp/madeimg/datasheet/a-110.pdf The following information comes from the website: http://www.w3am.com/8poleapf.html