The difference between the AL1, AL2 and AL3 Mast Systems is the OD (Outside Diameter) and wall thickness of the center mast poles.
The AL1 and AL2 Center Mast Poles both have a 2 inch OD, but the AL2 Center Mast Poles are 2x the wall thickness and can support more deployable weight than the AL1 Center Mast Poles.
The AL3 Center Mast Poles have a 3.5 Inch OD and can support the heaviest deployable payloads of all BlueSky Mast Systems.
Visit our Mast System Overview page to find out which system is right for you.