Illustrative canopy view. Nominal tube size alone does not establish total system performance or weather suitability.
30 mm is not one product
BST is value-focused steel, AUT adds assisted opening, and ALU changes the material and weight. A shared nominal leg width does not make the frames interchangeable.
40 mm addresses a different priority
THI is the thicker, heavier steel range. It is the first comparison for rental fleets and repeated commercial handling.
Ask for the full frame specification
Confirm outer and inner leg dimensions, cross-brace section, tube thickness, connectors, feet, hardware and model weight.
Frequently asked questions
Is 40 mm always the best choice?+
No. Buyers may prefer a 30 mm system for cost, lower weight or assisted setup.
Can roofs interchange between 30 mm and 40 mm frames?+
Do not assume so. Confirm roof geometry and attachment against the exact frame model.