As you can see in the above photo, Straight Leg Cuffs (also known as Nascar Cuffs or Boot Cuffs) give your racing suit the appearance of a normal lower pant leg (like you jeans). It gives your suit leg cuff area that "Taylored Look." The crow 2-layer Proban racing suits and also the multi-layer Nomex racing suit has a hidden elastic stirrup underneath the pant cuff that pulls down on the pant leg cuff, keeping it down on your racing shoes/boots so you're always protected!
Hidden Boot Cuffs only apply to the leg cuffs (not arm cuffs).