az4x alloy construction provides increased strength and a higher response ratemulti-variable wall design creates an expanded sweet spot and thinner barrel walls that are more forgiving after off-centered contactsecond-generation av2 anti-vibration knob features an upgraded, finely tuned harmonic dampening system for better feel and less negative vibrational feedbackring-free barrel technology offers greater performance with no “dead” spotsone-piece allot construction provides a clean, consistent, traditional feel