Product Overview Shooters that have already invested in a third party Arca-compatible ball or pan head can now exploit the benefits of the Spartan magnetic rifle attachment system. Made from CNC machined 7075-T7531 aluminium with a durable hard-anodised finish, the Spartan Precision Equipment Arca to Spartan 12mm Convertor attaches quickly and securely and is compatible with all Spartan Classic adapters, enabling rapid rifle attachment.