Never forget your bike pump at home again. The BioLogic Post Pump is an ingenious combination of a seatpost and powerful floor pump. The pump mechanism is hidden inside the seatpost and uses the seatpost as the outer wall of the pump. Go over 100 psi in less than half the strokes of the best mini-pumps. The PostPump is always ready, hidden from the elements and thieves. Black Supplied Suitable for all models with 27.2mm,31.6mm mm or 33.9 mm seatposts.