TA only make their chainrings from the best 7075 T6 heat treated aluminium. The teeth are cut in the traditional manner on a lathe which produces a much better and more accurate tooth form than pressing which is used by most chainring manufacturers.Features:* SPACING: 110mm PCD* COMPATIBILITY: Inner Double* Arm/Speed: 5-Arm 8x/9x/10x* MATERIAL: 7075 T6**Note: Zephyr Inner chainrings are suitable for 11x, only when it is paired with an outer 11x chainring.**