The Marble Arms Glow 50-W Front Sight features precision .500 inch fiber optic technology with a bright orange insert for enhanced target acquisition in various lighting conditions.Marble Arms Glow 50-W Front Sight.500 inch diameter fiber optic insertDurable steel constructionBright orange fiber optic for maximum visibilityProfessional grade rifle sight componentDesigned for competitive shooters and hunting applications where fast accurate target acquisition is essential. The fiber optic technology gathers ambient light to create a bright aiming point.