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Brand Name : ZRACE
Material : Carbon Fibre
Handlebar Clamp Diameter : 28.1 - 29.5mm
Height : 15 - 25mm
Fork Clamp Diameter : 28.2

Perhaps this is the world's lightest Stem Top Cap, with an actual weight of less than 4g.

Brand: ZRACE
Material: 7075 aluminum alloy, screw/titanium alloy
Process: 3D forging + CNC
Compatibility: MTB/ROAD