The new Maxima RED® SD is a breakthrough in controlling Dynamic Spine in a smaller diameter (.203"ID) shaft. The new, high-tech carbon arrow shaft design has stiffer ends to contain the arrow's flex to what we call the RED ZONE®. The RED ZONE is the section of the arrow shaft engineered to contain Dynamic Spine and make a broadhead shoot more consistently. The smaller diameter Maxima RED® SD delivers improved penetration and reduces wind-drift which enables more accurate shots at longer distances.