works fine, left scope out on a dewy night with it on lowest after an hour or so dew had formed on objective lens, to be fair heater tape was barely warm. turned it up and checked 30 mins later and the dew was gone. so on a night with minimal dew i think low power might be enough, on cold nights with lots of dew it might be a case of full power, but it does seem variable enough to control the heater tape so that you can use it without wasting energy, which if you are running of a power pack, i would imagine is kind of useful. obviously it has only a single controller but has two ports so you can run two heater tapes, only used on a 4 inch scope so cant comment on how it would perform on larger scopes with larger dew tapes requiring more power, but i believe it would cope ok. build quality seems ok considering the price, certainly not the most expensive dew heater

Very good piece of hardware, although it simplicity does a job very well

Very simple...Plug and play . Does the job perfectly ....looks good as well !

Had 3+ years use out of mine and it has served me well. Adjustment is easy and works great. Good value at this price.

Looks a quality item but I haven't had the opportunity to use it yet