Military Thermals long underwear complies with the US Military’s Battle Dress Uniform (B.D.U.) standard of sizing. As such, there are some size characteristics to be aware of. The sleeve length tends to run short, by design. The purpose of leaving the sleeve length shorter is to ensure that layered clothing does not start to stack up at the cuff. The thermals, being the base layer, have the sleeves terminate higher on the wrist to leave room for the outer layers. If you would like your sleeves a little longer, consider purchasing one size larger.