This Kit has been extremely popular with our customers for many years. The gunsmiths and dealers who do any type of sight work have found that they do not like to be without it. The slotted-head screws included in the kit cover at least 99% of all scope and iron sight mounting requirements.The Screw Kit is packed in a plastic box and contains 12 each of the most popular 18 screw sizes needed when working with scopes or sights. It also has a pair of chrome-plated tweezers with flat jaws for easily picking up the right screw and our handy, Checker/Shortener Jig that makes grinding screws to the right length fast and easy.The screws are made of high strength, forged tool steel, feature Mfg: Brownells SPECS: 216 slotted screws. Refills sold 12 per Pak. Metric equivalents for screw lengths: 5/32" (4.0mm), 3/16" (4.8mm), A 1/4" (6.3mm), 5/16" (7.9mm), 3/8" (9.5mm), 7/16" (11.1mm), A 1/2" (12.7mm).