I've been running this for a couple of months now on long (8hr+ sessions) and not had my secondary mirror dew up, even when everything else had a layer of frost over it! I run this at 12.8v continuously from my power bank and hardly uses any juice over a night. Very easy to fit and route the wire with the included tape/sticky pads. I have swapped the rca plugs for an xt30 just so it's a bit more secure. A really nice product to prolong a night out looking at the stars 🌟

Not used this in earnest as yet but it warms up! Power output of the smaller version is 1.6Watts at 12V and requires 14V to get 2Watts, I propose to use this with a PWM power controller and Li ion battery pack. Once I had found the instructions on on 4tronix web site installation was ok, although it would have been helpful if they had provided some cotton gloves which cost very little but who has a pair of these hanging around the house? Very neat looking once installed and cable is easily hidden along the edge of a spider leg. I am looking forward to giving it a trial.

Sizes of the 200PDS and 150PDS secondary mirror holders are identical and the dew heater fits this also.

Simple to fit , everything needed supplied , my only thing I would change is the cable I would prefer a single cable from dew heater to controller or at least an option when ordering also add a few self adhesive cable clips to allow for cable to be attached to ota , I modified a hole used to keep white trim in so I could pass cable out ota and still use ota end cap, easily modified with a flat file also you need to groove the plastic trim so allowing cable space without snagging ,

Works really well and took just moments to fit!