I have a custom Keen Add on Rib that was made for a K80 34" standard step rib barrel that makes the rib as high as the standard Trap Special unsingle rib so you can use a Trap Special stock with it. This is an aluminum rib and is 5/8" high at the step and goes down to 3/8". Save money with using this rib if you want a TS unsingle style barrel instead of spending $5000 for a barrel. (( $150 Delivered to your address in the Lower 48 )) Any questions please send a conv message for info and contact # - Thanks Bob