I have a used Pegasus Thruster for sale. Everything you need to start using this is included : the unit, 1 battery, charger, mounting tank-bracket, operating manual/kit, throttle cable, and spare o-rings. It is in great working order with no problems and was just serviced by the manufacturer this past January. These scooters mount to your tanks and leave your hands free for doing photography/video/spearfishing etc. You can find more information here:
