

The seat tube is the pump body, and the handle is inside covered by a screw on cap.
A hose with a schrader end, pulls out. You put your foot on the the angled piece on the floor and use the seat as a handle to pump away. It is as good as a floor pump. Clever and practical design. Dahon puts them on some of their top end models (though sadly not the lowly Boardwalk).