Superior Strength D.I.D's #1 VX Series includes the 428VX, 520VX3, 525VX3, and 530VX3 chains to for numerous street and off road motorcycles from 350cc to 1100cc. Longer Wear Life D.I.D's VX Series boasts a much longer chain life than the VO Series due to the patented X-Ring technology. The 520VX3 has a 32% longer chain life than the 520VO and the 525 and 530VX3 has a 41% longer chain life!" Quick Response This series has increased pin rigidity to help reduce flex, allowing for a more smooth ride and great throttle response.