Loose fit but, fixable - NcSTAR ShotGun Rails Bayonet Mount Remington 870

So, taking it out of the box, it looks like it’s quality built. The whole thing is made out of steel. The one problem is, it does not fit on the Mossberg 500 or 590 like it’s supposed to. All the way tightened, it still easily moves freely along the mag tube. It is fixable though. Just put some tape around the area you want to place it and tighten over the tape.