Side saddle with the most capacity and a rail - ATI Outdoors Halo Side Saddle Gen 2

I was looking for a side saddle for my Mossberg 590A1. After hours of research, I saw that Mossberg offers an ATI side saddle on their Scorpion 500 model. I was able to hold a Scorpion 500 at my LGS. I liked how the saddle mounted and fit the receiver. If Mossberg offers ATI parts from the factory, then
I knew this would fit with no problems. This particular saddle is made of metal and holds an additional 9 rounds [6 on the left side and 3 on the right] compared to other saddles that hold between 4-6 rounds. The metal frame wraps around the receiver like a cage for a secure fit. It also uses existing holes in the receiver for mounting. If your 500/590 has screws milled in to the top of the receiver, this installs easily. If you don't have the factory holes, the receiver will need to be drilled and tapped by a gunsmith.