3D forged AL6061-T6 alloy construction 4-bolt, 2-piece faceplate design Road or Mountain compatible Includes shims for 25.4mm bars ISO-Mountain safety certified 135g (110mm) Road or Mountain 1 or 1-1/8` 110 25.4 or 31.8 +/- 35? Sil Ano. AL6061-T6 Polished