The labels that appear inside our products can vary in terminology.  This is most commonly due to our vendors using their own ‘in-house’ labeling that can appear to signify different sizing.  Rest assured that all of our products are true big and tall sizing so whether the size label reads ‘2X’ or ‘2XB’ the measurements are that of a 2X Big. Subsequently, this remains true for all sizes 2XB-5XB. There are no substantial differences outside of acknowledged tolerances that occur during manufacturing.  Under Armour is a notable exception because they merely extend their sizes as opposed to making them in true big and tall dimensions.  We recommend sizing up in this brand for a fit more in-line with our other brands.