Stellarvue dual hinged rings for our 130 mm refractors. Used on our SV/SVA130 refractors, these rings work with 5.5" O.D. tubes. They are not sized for other brands telescopes. The rings have five 1/4-20 threaded holes top and bottom. This includes a center hole, two holes that are 1.5” apart and two holes that are 60 mm apart.