I just checked into it. It is simply an ambient air temperature reading, not infrared, so it does not really take the temp of the belt but the air around the sensor. Essentially worthless unless you want to know the air temp around the clutches or under hood.
From Amazon.
Question:
Is this one infrared or does it just measure the ambient air temperature in the housing?
Answer:
This will measure the ambient air temp inside of the CVT cover. Trail Tech does not offer an infrared sensor.
By Customer Service
Manufacturer on September 29, 2020
Start it around 6 min if you want to see the difference. SXS says don't waste you money on a air temp guage, and that's on a utv in the air outlet. On a sled forget about it.