The DVR108 from Losmandy are a pair of 4.25" (108mm) guide scope rings designed to attach a guide scope to your telescope kit.

The rings attach to Losmandy D-series and Vixen V-series plates via a tool-less dovetail clamp on the bottom of each ring. Once attached, the guide scope may be inserted into the rings and adjusted via three 7075 aluminum positioning screws which feature 1/4" Delrin tips. The I.D. range of these rings is from 2.96" to 4.32".