Sky-Watcher Moon Filter

A must have for Moon observation, which will really appear way too bright without. If you've got a large aperture telescope, this is a must-have. You can also use it for planet gazing, i.e. Jupiter.

Good set of simple glass filters. They all screwed directly onto my 1.25 inch eyepieces. I tried them on Celestron and Skywatcher Plossl eyepieces. They also fitted the cheaper Kellner eyepieces as well. All of the filters fitted perfectly - I had no issues at all with them. No additional data was supplied with the set, simply the colour of the filter. Metal frame as described. Very happy with the purchase.

First impressions aren't good... The filter arrives in a padded envelope, inside which there is a flattened plain white box featuring a Celestron label, containing a ziploc plastic bag with the filter within. The delivery note advises that this is "eco packaging", and to be fair the filter itself is undamaged.

Your money buys you a small plastic disc, an opaque core surrounded by a black border with the word "moon" on one side. The rear of the disc has screw threads, and what you have to do...