Nine choke constrictions let you precisely match load and shooting conditions, in a black oxidized finish. Minimum gap geometry and high resolution RMS interior finishes gives less pellet deformation; consistently tighter patterns. Perfect for shooters who need the original spectrum choke, but with the sharp black oxidized finish. Choke constriction is laser marked, on color-coded band so there is no need to remove choke to verify size. Long tube with hidden wrench slots extends beyond the length of the muzzle. Knurled grasping band speeds installation and removal. Helical rifled Diffusion spreader tubes provide a pattern that is more open than cylinder.