It's like sitting on air. Literally...yet...somehow minus the perceived comfort of actually sitting on air. Because although BioLogic's PostPump 2.0 has converted a high-capacity bicycle tire pump into a bicycle seat post, the end result still looks like it's going to balance the large surface area of my ass on the small surface area of a saddle such that, after approximately 2 minutes, I will develop the sensation of a blunt rod digging into my crotch rather than the sweet nothingness of air.
But if I get a flat, I'm golden.
The PostPump has been ergonomically designed to use its attached saddle as a handle so users can stand comfortably during pumping. Inflation time runs about 40 strokes to reach 50 psi in a 20" × 1-1/2" tire. The pump has a precision-machined aluminum adapter that fits both Presta and Schrader valves, and was built for Tern bicycles with an inner seat tube diameter of 33.9 mm.
Muchas danke to Bless This Stuff.