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 Big Z Line (Pearly) Plastic
Most durable, truer flights, last 2-3 times longer than base plastics. This is the slightly opaque Z-Line blend with a pearly appearance.