ARCTIC Aqua Rider 305 Radio-Controlled Boat, Water-Cooling System, 1:25 Scale - Black Knight 1:25 scale RC watercraft driven by powerful 9.6V rechargeable battery pack Mono-hull for easy maneuverability, water-tight compartment protects electronics Built-in water-cooling system pumping in water while running to cool down motor Optional T-01 digital dual channel radio transmitter Depending on the skill of the operator and the condition of the water surface, ARCTIC Aqua Rider 305 can reach the top speed of about 20 MPH.