500 gram zipper cakes are designed for rapid fire movement in a zig-zag pattern usually containing way over the usual amount of shots in most 500 gram cakes. These 500 gram fireworks are a breed of their own! They are much faster shooting than their other 500 gram counterparts. A zipper or sprinkler cake is exactly what you're probably thinking it is... a fast moving shot that goes from left to right in most cases, just like your lawn sprinkler. They have many different effects and types of shots. These fireworks effects range from small roman candle balls to mines to shells. They're the fastest, most exciting, fireworks on the market today.