Up for "auction" is an aftermarket mag tube cap with swivel stud that fits a 20 ga Remington 870, 1100, or 11-87. Condition is new in package. I have one of these on a Mossberg and it has been rock solid. I bought it for an 870 clone and it did not fit. The place I bought it from wants almost what i paid for it for restocking. I'd rather give it away than do that. Lets say $5 for shipping.