ForSale: The site will not let me say what type of air tube/compression tube it is as it's a cuss word (to this site) starts with a. B. It is not aluminum like the cheaper models that filled. Look inside the cocking handle slot you can see it is gold colored. This 717 needs a rear sight. Very inexpensive sight. It holds air and functions but it is probably best as a restoration project and either strip and redo the black or polish the pistol up. They look fantastic polished! I only take online payments at this time as here in Indy some mail has literally been running behind for over a month and a half. Mail has just been sitting in boxes at a PO hub. The story probably made national news. So Zelle,PayPal or Ca$h app only. E for more pics/questions and for my phone number