The Punishment Mask was listed on the Rust item store for only a couple hours before it was removed for a copyright claim. In the short time it was available, approximately 300 copies sold which made the skin incredibly rare, and those who own it are reluctant to sell.
The Punishment Mask skin (originally named "4 Deuces Skull Mask" on the Steam Workshop) is designed after the Deuce Four skull logo. At the time that it was prematurely removed from the item store, it was believed to be a rip off of Marvel's Punisher logo.