This chain is the fattest I have ever seen. The chain is 1/2" wide and 1/2" pitch. I am thinking 20" BMX maybe. I am looking to find out what it would be used on maybe it's not for a bike, I just don't know. The chain has 2K on some links and KMC 415H on other links. The chain is around 44" or 45" long. Here is a couple pics.