What is a Duo?
DUO Quick Pac (Fits all bicycles two box system)
The Shipbikes.com DUO System ships most bikes (22–26?) in two smaller boxes instead of one oversized carton. Each box holds 40 lbs, weighs 7 lbs, and 
measures 49 × 10 × 29 in, avoiding oversize fees. Splitting boxes eases handling and reduces damage. Pack the frame (battery attached) and handlebars in one, wheels and parts in the other. Boxes fold flat for storage and recycle easily. Create one shipment for two UPS labels, then drop off, hand to a driver, or schedule pickup