The EGT probe consists of a special alloy sheath connected to a stainless steel clamp. The probe tip is installed in a small hole in the exhaust stack, secured by an adjustable clamp. Before drilling, ensure that nothing interferes with the probe, clamp, screw or wire. Center punch and pilot drill each hole in the exhaust stack with a No. 28 or 9/64” drill bit. Use caution while drilling perpendicular to the stack to prevent an elongated hole. NOTE: Tighten the clamp screw with hand-torque nut driver only.