Material: primary aluminum alloy with a high content of hardened and tempered silicon, barrel with silicon carbide coating in a galvanic nickel matrix and cross-polished with two passes of diamonds with very narrow tolerances Processing: on high precision numerical control machine tools Material: special primary silicon aluminum alloy with low thermal expansion with tin coating on the sliding walls Products reserved exclusively for competitions in places designated for them according to the provisions of the competent sporting authorities. We decline any responsibility for improper use Feedback is very important to us and helps us to offer a better service to buyers: We kindly ask you to contact us for any problem, before leaving negative or neutral feedback. If you do not express your sat.