The Complete Pro XTRA long version designed for longboards SUP s and longer STANDARD POLYESTER FLAT surfboards 7’6 to 9’0 with longer fin boxes The ELECTRODES ARE SACRAFICIAL AND NEED TO BE REPLACED AS THEY BECOME CORODED please maintain with rinsing each surf and use appropriate cleaning products to maintain these electrodes ! these are available as replacement parts , we recommend using the insert plugs and screws for these boards without deck pads , We do not recommend this for use with children or anyone very sensitive to electrical shocks ! please check the warnings on the packaging before use . Rpela systems are water activated and High-volume boards or units mounted above water level will require the additional Activation Plug.(EXCLUDING SOFTBOARDS or PLASTIC TYPE BOARDS OR BOARDS WITH CONVEX, CONAVE or NON-FLAT SURFACES)