Can be fitted with the following flat bases: • #50 - (4.500" long, .200/.232 thick) NOTE: #50 can be used with Top Mount Rings on double & single barrel shotguns with ribs thick enough for base screws. • #61 - (1.168" long, .360" thick) • #63B - (5.450" long, .370" thick) PARKER-HALE • 1000, 1000C, 1100, 1200, 1700 45 46 - • 2600 71 85 -