To get that Rock Hard pressure of 2 to 2 1/2 PSI that you should be running most high quality rafts at, you need a Rock Hard pump. Save time and energy pumping up your raft with the Rock Hard 4" heavy duty pump. This pump is made to last, constructed of heavy-duty UHMW and PVC components and uses a genuine O-ring seal. Fitted with a smaller more managable 7' non-kink hose that also stows more compact than other 4" pumps. Ten year guarantee.