The 117F4 is a line matching audio transformer intended for sound distribution systems. It is designed to couple a 4-ohm voice coil speaker to a 70V amplifier line output. This transformer has a maximum power rating of 4 watts and offers five primary power taps at 4W, 2W, 1W, 0.5W, and 0.25W to match speaker power requirements. Key performance characteristics include a frequency response of 100 Hz to 9 kHz, insertion loss of less than 2 dB, and distortion under 1.25% at 100 Hz. The unit features a horizontal channel bracket for mounting and solder lug terminals, making it ideal for various public address and background music applications.