Railmaster DHB20-8 8 ohm, 2 watt, 20mm x 20mm x 9.5mm(0.78” x 0.78” x 0.37”). Frequency range 200 – 20,000 Hz Keith 6 years ago Railmaster DHB20-8 8 ohm, 2 watt, 20mm x 20mm x 9.5mm(0.78” x 0.78” x 0.37”). Frequency range 200 – 20,000 Hz