Each PRO mat is unique and there are a couple of reasons for why your PRO may be slightly shorter than 71":1. The PRO Series are all hand-finished during production, which means we have a slight allowed variance for the length of the mats. Some mats may therefore be slightly shorter, however we are confident that this will not have any impact on the performance of the PRO mat!2. The PRO Series are made with an internal scrim - a woven layer that gives the mat its shape and keeps it from stretching. Depending on how tight the scrim is, the mat can, over time, pull the mat slightly tighter causing it to shrink slightly. 3. You have a PRO mat from our Almost Perfect Collection - awesome! The Almost Perfect mats can be shorter and have a slightly larger deviation than our standard PRO mats. But don't worry - all these mats have been quality tested and have the same performance as the standard PRO mats.