Dock Edge + Inc. ProDock Commercial Grade Dock Bumper is an exceptionally strong Profile that is further reinforced by two internal supports. Like all DOCK EDGE + Profiles, it is constructed of marine grade flexible PVC, and developed not to chip or crack under normal usage. It is unaffected by oil, gas or salt water. This dock bumper has UV and fungus Inhibitors to prevent fading, yellowing, deterioration from sunlight and unsightly blotching.