All Cromartie supplied KilnMaster kilns are fitted with both control relays and security relays.
Cromartie recommend when changing elements to also change the control relays as part of a rigorous preventive maintenance routine.
These relays are also used in other manufactures brands such as L&L, Paragon, Olympic, Even Heat, Amaco, Cress, Tucker etc. Before purchasing check this is the correct relay for your particular kiln.