Arid Products is working on a new style of shotgun side saddle. Rather than use a permanently installed side saddle or the nylon webbing made shotgun shell cards with velcro, they are making metal detachable side saddles with a quick detach base mounted to the receiver of a Reminington 870 shotgun. They do have plans to make them for Mossberg 500/590s as well.
They do not have a website yet and no projected MSRP. However you can follow them on Facebook or Instagram.