Our most economical magnetic sight, the S-Series offers the bare basics to a shooter who knows exactly what color sight he likes. This sight presents a bright, affordable sight picture to any shotgun shooter. LitePipes are not interchangeable, so what you see is what you get. Narrow Model (S300) fits ribs from 0.218 to 0.328 (7/32 to 21/64) (5.5mm to 8.3mm).