OSE Heavy Duty upgraded flex cable for ProBoat Nitro Boats : Shockwave 36 & Thundercat 31, SW36, TC31 3/16"(.187) Cable with 3/16" propeller shaft. From end to end the entire unit measures 11.5". The Prop shaft is 3.75" long. This is the upgrade replacement part for the ProBoat Shockave 36 & ProBoat Thunder Cat but can but used with other boats. Required: Drive Dog, We suggest oct-oc6dm for the Shockwave and Thundercat.5mm prop nut pn# mc-94205A230