The ATWB1, K-type wet bulb thermocouple can clip to HVAC/R equipment for convenient placement and hands free testing. Wet the durable sock and clip to evaporator filters for indoor wet bulb great for finding target evaporator exit temperature. Clip to return vents for indoor wet bulb temperature great for target superheat calculations. The ATWB1 can be used with any of our meters that measure temperature and any thermometer accepting a K-type thermocouple. HVAC/R technicians find the ATWB1 extremely helpful when data logging or anytime an extra hand is needed.