What is the volume capacity of this luggage?

The volume capacity is 34 liters.

What are the dimensions of the Swissdigital BASEL Black Underseat Luggage?

The dimensions are 14 inches in height, 13.5 inches in width, and 7.5 inches in depth.

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Swissdigital BASEL Black Underseat Luggage - USB Charging Port - TSA-Friendly with Pouch Design - Padded Pocket for 13" Laptop SD-4000