The Magituner comes in two formats, the A model which is used with random lengths of wire and the B model which is used with old CB verticals.
Both models are rated at 400W CW or 550W PEP and are IP65 rated so can be used on marine vessels.
The A model can be used with any length of wire >=8m. With an 8m length it will tune from 40m - 6m and at >=10m from 80m and up.
The B model has two SO239 sockets and can be screwed onto the bottom (feedpoint) of a CB 1/2 wave or 5/8 wave such as the Silver Rod. You will need to remove the coil from inside the bottom section of the CB vertical though. This will then give you a multiband vertical that can be used from 40m - 6m with a 1/2 wave vertical and 80m to 10m with a 5/8 wave vertical.