Thrusters give you total control of your boat when docking and departing regardless of wind or current conditons. No reservoir to install, no leaks and no maintenanceHigh integrity sealBlack box electronics protect motorHardened and ground spiral bevel gear for maximum efficiency and quiet power transmissionSelf resetting thermal protection on all motorsEasy plug together switch connectionsMinimum silhouette hub for smooth water flowIncludes a spline driven, high performance, 5-blade propeller which gives equal thrust in both directionsA complete system requires a thruster unit, control panel, control cable, fuse holder, fuse and tunnel.