Majoni "Roll-A-Boat" boat rollers are made in Holland from thick heavy-duty PVC material. For moving boats across sand or beaches Etc. At least 2 rollers should be used, depending on the type, length and weight of the boat. 2 models are available that are suitable for a range of craft from small boats to surf boats and other craft to a maximum of either 500Kg or 650Kg weight when fully laden including all onboard articles and outboard motor, if applicable. Inflate with an air compressor - or a bike pump adaptor is available listed below. Heavy Duty PVC (Long) - Tough thick red PVC material. 650 Kg maximum weight. 1 metre x 260mm when inflated.