When I worked at a lfs in college, we had the biggest pistol shrimp I have ever seen. It was bright red and at least 2" maybe 3" long. I would get it to snap for customers and you could hear it all the way up at the front of the store, about 25 feet away. It was in a glass tank for months and it never broke. If there was ever a pistol that could break glass it was this one!!