Parts Express 10W Corded Electric Speaker Line Matching Transformer, 3.0 amps, 100 Hz - 12 kHz, 300-040, 0.88 lbs
Constant voltage, isolated line matching transformer for use with public address amplifiers utilizing a 70.7 volt or 25 volt carrier line for sound transmission. Frequency response: 100-12,000 Hz. Secondary impedance: 4 or 8 ohms. Tap at 0.62W, 1.25W, 2.5W, 5W and 10W.