This unusual device appears to be some sort of amulet worn as a choker necklace. However, sharp barbs point inward, and look capable of shredding muscle and flesh.

Each time you don a blood claw choker, it deals 1 point of damage to you. This damage can’t be healed as long as you wear the item.
A blood claw choker grants you a +2 enhancement bonus to your Constitution score. This effect functions continuously.
In addition, when you activate a blood claw choker, you regain any one sorcerer spell slot that you have already used today (up to a maximum of 5th level). The slot becomes available as if you had never cast a spell of that level. At the time you activate it, the choker deals damage to you equal to twice the level of the spell slot regained.
This ability functions twice per day.

Prerequisites: Craft Wondrous Item, bear’s endurance, vampiric touch, possession of a piece of the set.
Cost to Create: 6,000 gp, 480 XP, 12 days.