The retro core and ultra strong reactive coverstock has always defined the Avalanche series from Brunswick. The Avalanche delivers unprecedented value to the bowling customer. Core: All Avalanche balls use the acclaimed light bulb core initially used in the Teal Rhino Pro®. The light bulb core and its Danger Zone® modification were at the heart of two of the most successful balls of all time. Coverstock: The Avalanche Slide uses the brand new PowrKoil XD Reactive coverstock,designed to provide extra distance (XD) through the heads when compared to the traditional PowrKoil coverstock. Combined with the light bulb core, the PowrKoil XD coverstock of the Avalanche Slide gets cleanly through the heads, even on broken down lane conditions, while maintaining the strong back-end reaction necessary to bury the pins in the pit.