Decided to upgrade my dovetail bar mount on my Sky watcher Evostar 90, as it wasn't particularly well balanced when using heavy eye pieces. Sky watcher had a cheaper set of rings available, but having an Altair scope with machined aluminium tube rings which are great quality I decided to spend more than I wanted to on these tube rings and I wasn't disappointed. The quality and finish of the product is excellent, the fit around the scopes tube is perfect, once the thumb screws are tightened up it feels really secure, coupled with an Altair carry handle I feel very confident transporting the scope around and knowing that it will attach firmly to my mount and I can balance the scope correctly.