Leupold Cross-Slot mounting systems feature Weaver-style rings that work with both Weaver or Picatinny rails with 1-piece and 2-piece bases available for many popular rifles. This model is designed to fit any riflescope with 1 maintube and is ideal for standard to magnum calibers. The PRW2 mounts are very popular since many rifles come with Weaver-style bases or cross-slot rails.