The StellarVue F2D Dovetail Base and Stalk was designed specifically for Multi-Reticle finders and fits most standard Synta style dovetail shoes found on Chinese focusers (like the ED80) and imported reflectors. The dovetail base measures 1 3/16" maximum width and will work in most dovetail holders that are this size and wider. (F2 or F2-MRF Finder sold separately.) Its all aluminum construction holds the finder above any obstructions and you're ready to use your F2 illuminated finderscope fast and easy! Does not fit Stellarvue F1001 Red Dot Finder.