High strength, steel bases to fit a wide range of modern and older rifles plus, some long range handguns. Sold each, order front and rear base. Front and rear extension bases provide added flexibility for mounting all types of scopes.S35 Base fits BSA – Monarch med./long action. S36: Rear; S35: Front. Churchill – Highlander. S36: Rear; S35: Front. Colt Sauer. S35: Front & Rear. Enfield Receiver cut down like: Remington 721. S36: Rear; S35: Front. H&R 317, 322. S35: Front. Herter’s U-9 round receiver. S36: Rear; S35: Front. Howa 1500. S36: Rear; S35: Front. Mossberg 1500, 1550, 1700. S36: Rear; S35: Front. Raptor Arms &nda Mfg: Weaver SPECS: Steel, blue, matte finish. Fits Weaver Grand Slam, Top Mount, Tip-Off and See-Thru Mount Rings. Includes screws.