Design Registrations Our Certificates of design registration are issued by Workcover NSW, and are valid Australia wide. 244 diameter End Fill Cylinders.270 diameter Cylinders.270 diameter End Fill Cylinders.315 diameter Cylinders.360 diameter Cylinders.400 diameter Cylinders.585 Internal Toridals.600 Internal Toridals.650 Internal Toridals.650 External Toridals.680 Internal Toridals.720 Internal Toridals.650 Four Valve External Toroidals.680 Four Valve External Toroidals.720 Four Valve External Toroidals.