From the manufacturer's official website:

Alloy, carbon fiber wrapped.

Technical Data:

• Handlebar O.D.: Ø 31,7 mm (Newton standard)
• Fork steerer O.D.: Ø 28,6 mm (1’1/8)
• Extension angle: 82° degrees
• Weigth (120 mm size): 165 grams

For more information, please visit this product's webpage.