Thread this 3.5-Inch to 2-Inch Rotolock Visual Back Adapter onto the rear of a William Optics FLT refractor with a 3.5-inch rack and pinion focuser to upgrade it for use with a 2-inch diagonal or other 2-inch accessories.
This 3.5-Inch Rotolock eliminates the need for compression rings. A supplementary 2-inch to 1.25-inch adapter is also available but does not come with this system. To lock and center an inserted 2-inch accessory in place, simply rotate the adapter ring clockwise. Rotate counterclockwise to remove the accessory. Installs in mere seconds! A mild clicking noise from the internal ball bearings indicate when the visual back is opening and closing, providing easy operation at night.
Image Note:The supplementary 2-inch to 1.25-inch adapter is also available but does not come with this system.