This tube fits the following guns:
Mossberg 20ga 500, 505 
 
20ga Mossberg 500, 505 Anaconda Striker 0.570
 
Patternmaster Anaconda “STRIKER” (0.570”) 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 “STRIKER” will throw an Extra Full pattern with distances out to 60 yards. This tube is safe and effective with non-toxic shot as well as lead. 
Note: Testing done by Ballistics Performance has determined that ammunition with velocity of 1550fps and below will achieve the best results with Patternmaster Tubes.
Not for use with slug ammunition.
NOT FOR USE WITH STEEL SHOT