Surgical steel acrylic industrial barbell. Project bars work for multiple piercings. Simply insert each end of the barbell into each hole to wear piercing. Remember, do not pull through the hole.. Specifications: 14 Gauge (1.6mm), 1 1/4" (31mm), 316L Surgical Grade Stainless Steel, Acrylic 5mm Balls. Black Marble Industrial Barbell 31mm