Leupold LRW cross-slot rings are built from Strike Forged Steel, made in America to deliver unmatched durability and strength. Leupold CNC machining ensures perfect alignment to Weaver-style bases and the anti-slip grooves eliminate the need of lapping. LRW ring screws with Nylok won't back out under recoil or vibration. Recommended for mounting on firearms such as tactical shotguns with built-in mounting rails. Strike forged rings for unmatched durability & strength Anti-slip grooves - no lapping required Cross-slot compatibility fits Weaver-style bases CNC machined for perfect alignment Locking screws with NYLOK - won't back out under recoil or vibration Made in the USA with a Mfg Lifetime Guarantee