Please note: This text was taken directly from the manufacturer.
Pair of cast-metal rings of 105mm inner diameter that attach to a mounting plate for Orion guidescopes of up to 80mm aperture. Each ring has three black nylon alignment screws, which will not scratch guidescope finish. Rings attach to mounting plate with two 1/4"-20 hex-head cap screws (included). A small wrench is also included.
Comentariul expertilor nostrii:
Inelele de ghidaj sunt ideale pentru refractoare de 80 mm. Pentru majoritatea refractoarelor de 70 mm acestea sunt prea mari. Cele 3 şuruburi de fixare sunt din plastic şi nu zgârie tubul de ghidare.
(Bernd Gährken)
These tube ring clamps are ideal for 80mm refractors, but are too large for most 70mm refractors. The 3 retaining screws are plastic to avoid any scratching with the finder scope.
(Bernd Gährken)