6061 T-6 Aluminum, Anodizing finished, with the carbon fiber warp up surface. Micro honed and mirror polished for the best accuracy Machined with bore match technology. This process ensures that the front half and the back half are in perfect alignment.Every time. -Autococker Thread. -7inch lenght.Fit the DYE Brand barrel type tips. -Available bore sizes: Customize 0.065kg Note: The barrel back Thread, bore size and colors,Can customize. Customize order need the MOQ.