This basic version of the AV-41 has a 2-1/2″ #10-32 stainless steel rod that enables the AV-41 scope to be used with both Axcel sight bodies as well as non-Axcel sight bodies. The AV-41 Plus accepts 44.5 mm lenses , and comes with the Axcel Lens Frame Retainer and two spacers for use in installing lenses, sight pins and crosshair .