Made from extruded 6061-T6 lightweight aluminium alloy. Northline offers top quality Hard Anodized Threaded Fittings ranging from 3/4" to 6". The finished product is laser engraved with a clear understanding of the thread type and size produced. Swivel sizes ranging from 1 1/2" to 3" are attached using ball bearings. Swivel Sizes ranging from 4" to 6" are attached using roller bearings.