Carefully crafted for compactness and lightness, this rail cap accessory is designed to work with a wide range of optic and accessory combinations. It enables the addition of both rail-mounted laser rangefinders and secondary aiming devices (red dots) to your magnified optic. This simple cap replacement fits all existing RPM products, including CLR series rings and Bravo/Delta cantilevers. The cap screws from the original purchase are the exact ones needed for installation.