Bought from a local vendor. Tested on a box with dual evaporators and a fan motor. Pros: Anemometer works great. Cons: The arm fell off while waiting for it to read the same 35.3 degree temperature as a Fieldpiece HS33 multimeter with an attached ATA1 Type-k thermocouple. seconds. I would NOT recommend this device if a fast enough temperature reading has anything to do with your purchasing decision.