Mychron 3, 4, 5, 6, Black Patch Cable Sold Separate 10mm Water Temperature Sensor Only Threads into some engine heads (Rotax, IAME X30, Leopard and others) or can be used with Mychron or Wild Kart Inline Water Line Coupler Works with Mychron 3, Mychron 4, Mychron 5, Mychron 6 with proper patch cable M3, M4, M5, M6 Thermo Resistor