This is the RTD Probe that will sense the temperature inside the barrel and relay this back to the control board. This probe is located on the hopper side wall, inside the barrel covered by a shield to protect it from getting damaged.
Dimensions:
Probe Length: 3.5″
Cord: 20″
Mounting Plate: 1.75″ x 0.5″
In the manual for the Oklahoma Joe’s Rider DLX Pellet Grill 900 and 1200 models this is listed in the parts key as item #24.