The lens lightens or darkens quickly depending on the available light

A2 Spec has no marking at the top of the stanchion and the speed adjuster knob is black (vs Silver for the A1)

Featuring Dynamic Chain Engagement

All you have to do is insert the tools pins into two links and look at the gauge

ProTaper Carbon Bars - Stealth - 31.8mm - 12.5 Rise - 810 Replace Images The lens lightens or darkensThe width of your bars can mean the difference between a quick response or going OTB. Wider bars means more maneuverability, more control, more leverage, more send but less room to squeeze between trees. ProTaper's carbon bars are 810mm wide but can be easily trimmed down to your preference using the pre marked cut lines. ProTaper's new bars are a light and dependable carbon bar featuring ProTaper technology to make strong clamp and riser sections