The Anaconda Gas Over Constriction Choke Tubes use constriction as well as the patented "Coil Zone" to wind gasses around the wad to assist in constricting and pattern uniformity. Patternmaster Anaconda has "Gas over Constriction Technology" within the patented "Coil Zone" made up of internal channels used to harness gas expelled from the ammunition. "Coil Zone" channels are spun in a negative twist to stabilize the wad for even, consistent patterns and keep the tube tight in the barrel. Anaconda SHORT range will throw an IMPROVED CYLINDER pattern with distances out to 40 yards. Anaconda MID range will throw a MODIFIED pattern with distances out to 50 yards. Anaconda LONG range will throw a FULL pattern with distances out to 60 yards. All of these tubes are safe and effective with steel or other non-toxic shot as well as lead shot. Not for use with slug ammunition. Short- 0.733", Mid- 0.715", Long- 0.700". FeaturesCoil Zo...