The Chain Reactor is a miniature version of the standard Axl, with the same features as the Reactor. It's performance and fun in a small package! For those looking to experiment with small-bodied yo-yos who prefer the modified convex shape, this is a great choice. Because we receive so many different colors of this yo-yo in such small quantities we cannot offer a color choice. However if you'd like to request a color, your more than welcome to. In 2008 Custom changed their bearing size to A. If you have an older Custom yo-yo you may need the old I bearing size.