Attached a few pictures showing this temperature gauge/switch. As you can see in the pictures, there is a red and black needle indicator. The black needle shows the current temperature of the blower. The red needle indicates the max temp the blower has reached, which is also resettable. It will follow the black needle on temp increase and remain in that location as temperature falls for a max temp indicator. You’ll also notice a small red arrow indicator set at 190F in these pictures. This is the temperature switch setpoint for the alarm signal. To adjust the setpoint open the black cap in the center of the gauge. You’ll see a brass flat head screw. This screw moves the clear indicator needle. When you push the brass screw inward with a flat head screwdriver this will allow the clear needle to catch the temp setpoint arrow allowing you to adjust its position.