Weaver Thumbnut  30Mm Scope Mounted Picatinny Adaptor Made of the highest quality materials Hunting scopes mounts Another quality Bushnell product Mounting platform on allows for easy install of accessories Picatinny spec allows for mounting Weaver-style or Picatinny-style rings 6061 T-6 Lightweight Aluminum Four hole mounting platform for added security Another quality product from Weaver