The Knockout: Ultimate Beer Bong Attachment The Knockout: The Ultimate Beer Bong Attachment. Turns any beer bottle into a beer bong! Tons of different uses! Beer shotgun, Water Pipe, Gravity Pipe, and more! High quality construction! Made of Food-Grade Silicone and Stainless Steel! Breaks down for easy transport and storage. Minimal assembly required. The ultimate party starter! Use The Knockout as a Beer Shotgun, Water Pipe, Gravity Pipe, and MORE!