Axcel Achieve XP Pro Recurve Sleeve Lock Block Black #8-32 Thread Compatible with Axcel Achieve XP Pro recurve sights;Ensures stability and secure positioning of the sight;Made from durable materials for long-lasting use;Standard #8-32 thread for a perfect fit;Sleek black finish to match the recurve sight aesthetics;8-32 threaded aperture block;Easy to change out apertures;High-quality construction;Secure fit for reliable performance