is their a noticeable difference from UM to 21-13? and why are they called 21-13? i know why he left UM but is their a reason behind 21-13? they look pretty sick though....which is better, billion air or agent?
21 is the numerical value for U and 13 is the numerical value for M
and yeah the agent has a little wider outline so it works awesome in alot of different conditions, the billion air is more like a standard surfboard so its just fast an really loose