The digiSOUND5mSDT is an RC boat sound module, it is the worlds first 100% waterproof, plug n play sound module designed to take the hassle out of giving your model a realistic sound! The sound module requires NO programming or set up, it comes with a realistic sound pre-installed leaving just the installation to complete before you can get under way! The unit comes complete with built in amplifier, wiring loom and even a 75.0mm diameter waterproof speaker! You simply install the unit in your model and go! There is no complicated PC interface to deal with or complicated set up, you REALLY do just have to plug it in and go!!! Add this to the legendary Mtroniks waterproof construction and you really don't need to look any further! This version of the digiSOUND comes with a pre installed, small diesel tug boat engine sound, this comes with a start up and shutdown routine and auxilliary horn for added realism, when used with the optional 'microswitcher' unit. The digiSound is the last piece of the jigsaw for adding realism to your RC model boat Notes on speaker performance. The 75.0mm speaker included with your module is waterproof so it is safe to use outside, you should always install your speaker into a suitable enclosure (the upper side of your hull) to ensure the best power handling, frequency and bass response.