No jamming! Designed NOT to overlap the shotgun's receiver when cycling the pump action, thereby reducing the chance of a a momentary jam by sling of clothing. Adapters included. (Will not fit Maverick 88)FITS: 12/20GA Mossberg 500*/535/590/835, Remington 870, Winchester 1200/1300 Note* Synthetic Forends on new Mossberg Model 500A cannot be replaced because action bars are attached to forend.