Discraft says this about the Undertaker: Discraft Stability Rating: Z-Line 1.4; Z Line FLX 1.4
Most players have one versatile driver they reach for most often, and Undertaker is the new choice. This straight flier fills many needs for many different skill levels: it doesn't get flippy for power throwers, isn't hard to control for low-power players. Great glide, smooth finish, nice grip, big wins.
About D-Line Plastic
Superior grip, great for beginners or pros, very economical, different amounts of wear yield desirable flight differences.