It seems that the ecowitt HP2553's Ultrasonic Anemometer Sensor Package comes with a heat plate built-in. To use it they suggest one contact support for extension cord information. In so doing they note "... if the lowest temperature at your place is below -3°C, or 26.6°F, …" Ambient weather now has Item # WS-5000-HEATER-AC listed as being out of stock currently. This "65' Heater for WS-5000 Ultrasonic Sensor Array" seems to include a heating element, an AC to DC power brick, and a 65 foot outdoor AC power cable. This implies that their WS-5000 does not come with a pre-installed heat plate. Interestingly ambient states that their heater solution cycles on and off at 50 °F. This kind of implies that ambient's implementation needs heating at some what higher temperatures than the ecowitt solution. Does anyone have an understanding about what's really going on here?