Too many modern mountain bike stems sacrifice strength and torsional stiffness for a few grams of saved weight. The Thomson X4 is the leader in strength and stiffness. The Thomson 35mm X4 stem allows you to realize the benefits of stiffer forks and stiffer 35mm bars. X4 offers precise steering, tracking and more control while riding, all wrapped up in a beautiful design. Certified to: CEN ISO 4210-5. The Thomson 35mm X4 is based on proven design. It features a traditional steerer clamp that is shaped to save weight and to be knee friendly. X4 is absolutely the best combination of strength and weight available. Thomson stems are the strongest in the industry, meaning enduro and downhill riders can run Thomson confidently.This stem body is forged AL7050 where every surface is machined. The faceplate is forged from AL6066 and 100% machined. It’s built and tested to the same standards as aerospace parts and it’s the best stem for all-around mountain biking.