裡面有一段我節錄於此 The XR-200 is KinLin company's lightest road rim, and one of the lightest aluminum rims on the market. The XR-200 features a box-shaped cross section for added strength - not the most aerodynamic rim on the market, but ideal for use in a climbing or weight-conscious wheelset. The XR-200 is extruded from a superlight Niobium-Aluminum alloy and joined with a high quality pinned joint. Finish work on these rims includes a high gloss anodization and machined sidewalls.