Bottle Popping Training Butterfly Knife Style Can Opener Satin Finish - Tophatter's Army Products & Self DefenseBottle Popping Training Knife styled Bottle Opener plus can opener tool. This is ideal for practicing your flipping safely and popping off bottle caps in the process. Imagine the look your friends will give you when they see you flip out this Bottle Popping and pop open a beer or soda cap. It is about 8. 5 inches long when open and the stainless steel is heat treated along with having a satin hard coat finish. Specifications Overall Length: 8. 4