If you happen to own an older Vixen 102mm refractor, particularly with the non hinged sprung tube rings, the very nice Vixen white carry handle fits on the top of the tube ring utilising the threaded hole in the top of the ring. These older rings use 1/4 UNC threading and I have attached the handle using a 1/4 x 11/8 (one and one eigth) inch stainless cap bolt hex head. I cautiously made sure the bolt did not contact the ota.
It seems new refractors rings may be M6, as the handle is supplied with a M6 bolt.
Vixen item # 3870
It is a very nice mod and allows very safe handling of the ota and ease of placing the dovetail into a mount.