Shotgun choke constrictions from Cylinder to Extra Full, in .005 inches (.127mm) increments let you precisely match your load to the shooting conditions, in a black oxidized finish. Long shotgun choke tube extends beyond the length of the muzzle, features highly polished interior for less pellet deformation; reduced fliers and tighter patterns. Knurled grasping band speeds installation and removal. Shotgun choke constriction is marked on band so there is no need to remove shotgun choke to verify size. Helical rifled Diffusion spreader shotgun choke tubes provide a pattern that is more open than cylinder.