TruGlo Strut Stopper Xtreme Choke Tube Combos -TruGlo Strut Stopper Xtreme Choke Tube Combo. This choke tube incorporates internal grooves and optimum constriction for super-tight patterns. -Winner of 11 NWTF World Still Target Championships -Holder of 7 NWTF World Records -Designed by four-time winner of NWTF World Still Target Championship -Internal grooves improve patterning -Optimum construction for tight, dense patterns -Precision CNC-machined -Accepts all turkey loads including Hevia Shot -Available in 20 ga. (limited models only) -No steel shot -Endorsed by the National Wild Turkey Federation - Combo Bonus - Free TruGlo Gobble Dot Universal Dual Color Turkey Sight! TruGlo's original turkey sight in Dual Color; Fits all ventilated rib shotguns regardless of width or tapering; Extremely low profile; Front diameter is .120"; rear diameter is .040"; Endorsed by the National Wild Turkey Federation;