Kenwood Original KES-5 External Mobile Speaker - Max. Input Power: 40 Watts, Impedance: 4 Ohms The Kenwood KES-5 mobile speaker is incredibly rugged meeting Military Standards 810C, D, E, F for: low pressure, high temperature, low temperature, temperature shock, solar radiation, humidity, salt fog, dust, vibration and shock! This 4 ohm speaker has a maximum input power of 40 watts. You will find these speakers in fire and rescue vehicles, dump trucks, police cars and ambulances Max. Input Power: 40 Watts, Impedance: 4 Ohms, Dimension (W x H x D): 129 x 129 x 77 mm (5 1/16" x 5 1/16" x 3")