The new RotoLock series of adapters from William Optics may well set the "gold' standard for visual backs and eyepiece adapters in the astronomy industry! Thoughtfully designed, exquisitely machined, and artfully presented, these adapters provide a very convenient and robust method to attach eyepieces and accessories to your telescope.
Just rotate the golden grip ring clockwise to lock any inserted accessory, or counter-clockwise to release the accessory. Innovative design ensures that you get a very solid hold and the accessory is perfectly centered every time. No thumbscrews to worry about!
This WO adapter # F-ROTO-A2-125 has a 1.25" eyepiece holder on one side and a 2" tapered barrel with standard M48 female filter threads (M48x0.75) on the other side.