Mirror finished Stainless Steel body. Internally threaded to accommodate two 11mm diameter black Delrin balls. All barbells bodies are internally threaded and each ball is studded and given a flat surface to match the gauge of the barbell body. Gauge: 6mm (2g) Lengths available: 10mm, 11mm, 12mm, 13mm, 14mm, 15mm 16mm. Ball diameter: 11mm Product Care Due to the material of the ball being softer than the steel studding, care should be taken not to over-tighten on assembly Care should be taken when purchasing our items due to the nature of the products and the intimacy. We offer many different sizes with a lot of our products, so please take care when choosing.