Berkey System offers a number of different 60mm Rail Blocks that can used to customize a new rig or be added to an existing rig. All of them are designed to be used with 15mm diameter rods spaced at 60mm. From the simple to the elaborate, we have the parts to create a truly custom rig for your specific needs. All Berkey System Rail Blocks are black anodized for durability. All Berkey System products are made in the USA and are covered by our Lifetime Warranty. See Terms and Conditions for details.