Boss Audio Systems MRWT40 is a 2-way fully marinized waketower/rollbar speaker system, including two 4-inch speakers with a 1-inch dome tweeter in each. With a power handling of 400 watts (max) and a frequency response of 130 Hz—20 kHz (+3 dB), these speakers are designed to deliver high-quality audio in marine environments. The MRWT40 speakers are 4 ohms impedance, so they can be connected to the output of a head unit or to a separate amplifier for optimum performance. They also feature 1-1/2" - 2" (38 - 51 mm) clamps for easy mounting on waketowers or rollbars.