Hastings 12 GA. PARADOX RIFLE SIGHT RIFLED BARREL
160H40 M-870 - 24" Rifle Sights - $165 + shipping
Has 6 shells thru it to sight it in.
Front ramp and blade front sight with all steel rear sight that is fully adjustable for elevation and windage.
ResidentPGH at Yahoo dot com
For reference: https://www.rrarms.com/catalog.php?prod=160H40 Hastings Paradox Slug Barrel Remington 870 12 Gauge 3" 24" Rifled with Rifle Sights Blue - MidwayUSA