Features a custom CNC-machined alloy top cap in the shape of the Box logo with cut outs to reduce weight. At the center of the top cap is an anodized aluminum bolt that threads into a gold anodized aluminum expander plug that eliminates the need for a star nut and works with all steerer tubes including carbon fiber. The top bearing cover is crafted from carbon fiber, which not only adds style, but helps to shave weight. At the heart of the headset are two super-smooth, titanium-nitride coated, sealed, 45x45 bearings. A split crown race makes installation and removal from forks super easy. Box 1.5 headsets are designed solely for tapered frames and forks IS42/28.6 | IS52/40 Blue 107g 28.6 42/52 39.8 45/45 1-1/8 to 1.5 LWH 2.20 x 2.25 x 2.25