This is the Temperature Sensor for the Traxxas EZ-Peak Plus Charger, TRAP2933.
Temperature Sensor with Instructions
Enables the use of temperature cut off feature on any Traxxas
charger equipped with temperature sensing
Compatible with NiMH and LiPo battery chemistry
Maximum Recommended Temperature Cut-Off Settings:
LiPo, 110°F (43°C)
NiMH, 120°F (49°C)