PETZL Carabiner Petzl Carabiner Set of 2 medium-sized aluminum carabiners with a safety locking mechanism. Petzl (PETZL) BL William Ball-Lock Petzl Carabiner AMD Ball-Lock I received these two years ago, but I have never used them. - Features: Safety locking mechanism - Type: Locking carabiner - Material: Aluminum - Color: Silver - Size: Medium "Please be sure to check the condition of the product in the images provided and only purchase if you are satisfied."