PA2 is a Putt and Approach disc. This Putt and Approach disc is designed to be stable to over stable in all wind conditions. The consistent flight path of this disc makes it extremely reliable in all wind conditions.
The 400G series is the regular 400 plastic with a shot of adrenaline. It is the base 400 plastic mixed with another resin that give the plastic a slightly different feel than the base 400 series. The additive also makes the disc more durable and requires more time to break it in.