This Accuracy Systems Heavy Duty Action Tube fits all Remington Model 7600's & Model 6's. The thicker walls means no more stretched hole's from installation or disassembly. FeaturesHeavy Duty refinements.Through Holes have been located closer to the center of the tube for easier access. (Yellow Arrow)Metal wall thickness is .125" compared to the OEM factory Remington .0625". (Green Arrow)Comes with rubber O ring.