PISTON KIT VERTEX YAMAHA YZ125 05-21 YZ125X 20-21 53.94MMVertex 2 Stroke Piston Kits OEM equipment in KTM & Husqvarna The Vertex formula for delivering better on the track performance is simple ? precision equals performance. It all begins with precision engineering based on more than 50 years of experience in the design of OEM quality and championship proven replacement pistons. The commitment to precision continues throughout the manufacturing process where every Vertex piston is given an advanced