Black Circular Barbell Black Stainless Steel Sizes: 16 Gauge (1.2mm), 12 Gauge (2mm), 8 Gauge (3mm), 6 Gauge (4mm), 4 Gauge (5mm), 2 Gauge (6mm) Length: 3/4" (19mm), 5/8" (16mm), 1/2" (13mm), 3/8" (10mm)