Simple, economic replacement set- Cold forged 7075 T6 aluminum and hard anodized for durability- LevaTime: Praxis unique timing and shifting technology- Not compatible with Campagnolo/Fulcrum Ultra Torque/Racing Torque cranksets- * 32/48t rings: this is a custom ring set that can only be installed on the new Praxis Works branded 110BCD road cranks, and also the new Specialized alloy 110BCD spider. This specific set includes custom bolts required for installation. This set will not install on prior generation "TURN" road cranks or other brand cranks.* 32/48t rings: This is a custom ring set that can only be installed on the new Praxis Works branded 110BCD road cranks, and on some Specialized alloy 110BCD spider. This specific set includes custom bolts required for installation. This set will not install on prior generation "TURN" road cranks or other brand cranks.