Have used this sight for 12-14 years with great success and zero problems. Adjustable for both vertical and horizontal POI. All steel and VERY, VERY durable and attaches VERY securly, mine has never moved after over a decade of hunts and MANY dozens of shots.
tps://www.midwayusa.com/product/219733/truglo-pro-series-magnum-gobble-dot-sight-set-fits-remington-shotgun-with-1-4-vent-rib-steel-fiber-optic-red-front-green-rear
If my eyesight hadn't changed requiring I use a scope I would still be using it.
It would seem I can not post a link so it's the Truglo Pro-series Magnum Gobble Dot clamp on turkey sight for vent rib shotgun barrels. Rear sight is fully adjustable.