Replacement solenoid coils for Rocket espresso machines, available from Coffee Spares Direct. Solenoid coils commonly come in two different types, two way and three way. The two way acts as an automatic valve letting steam or water through when energised. The three way works in the same way but has a third outlet on the top of which relieves the pressure from the valve when not energised. Do not remove the coil and energise as this will burn the solenoid coil out. Coils or whole coils including the brass base and valve guides available, We sell all Rocket Espresso spares and accessories.