Site-Rite Features Get meticulous accuracy with the most exacting tolerance specifications in the sighting industry. From the very smallest to the largest 12 gauge casing the GSM Site-Rite precision machined caliber specific sighters deliver unparalleled results every single time. Site-Rite Specifications Precision machined brass casing for optimum accuracy Caliber specific factory alignment High output laser Units include (3) three Alkaline button cell batteries (varies by caliber)