I ordered the #Vevor boat fenders for mounting on our dock. The 5.5\" by 20\" size was perfect for horizontal mounting. I mounted the bumpers horizontally on the face of the dock so that any hull, mine and/or visitor, are protected. The winds can be quite severe on the lake and having this extra level of protection is well worth it. The bumpers arrive deflated and are made out of a thick, flexible vinyl (PVC). The package includes a pump and several needles needed to fill the bumpers. I was tempted to use an air compressor but was afraid of overfilling and possibly bursting the bumper. The included handpump makes quick work of filling the bumper with enough air to make them usable. I'm very happy with the quality and functionality of the Vevor bumpers and can see them lasting for years.