I had some issues mounting this on my TelRad. I am not sure if my TelRad is just rather wide but it is difficult to get the cover to mount properly because of the washers that protrude too much . If you can get it to mount then then the
plates bend out some. Once mounted it seems OK. Not had a chance to test its dew ability yet though.

Unfortunately I’ve found this doesn’t work very well. It doesn’t prevent dew from forming, though it does slow up the formation very slightly. It also works better if you take the mirror out which is disappointing. I’ve only used it a few times but I wouldn’t purchase it again.

The mirror gives just enough field of view to see stars that are outside the outer circle and gives a comfortable viewing position. I will be upgrading my other Telrads with this device

I bought the mirror version for my Dob. Every time that you move it, the screws come loose and being plastic you cannot tighten them much and it flops over. Being small and black bit difficult to do in the dark. Tried to tighten them and the housing split. However, superglue to the rescue. I modified the screws by making them thumbscrews using scrap plastic. All said, it does do the job.

Same as the Tetrad Finder the dew shield is AOK.brilliant delivery and service 10 out of 10 for me.Thankyou.