An impact absorption device is provided having a generally cylindrically shaped impact absorption member formed of an extruded material. The exterior wall defines an interior volume and further includes a flanged portion that extends to at least one end of the absorption member. A bracket assembly is removably secured to the flanged portion of the mounting member for attaching the impact absorption device to a freestanding object such as a piling or docking post. Due to the design of the flange of the absorption member, a plurality of members may be coupled together using an appropriately designed bracket for accommodating the cover of pilings of docking posts of various lengths.