Buoyancy: 310lbs · Heavy wall thickness (.150) nominal wall · One piece rotational molded shell · Completely foam filled 1.0-1.5 density EPS · Virgin grade polyethylene materials · UV inhibitors · Molded in Mounting slots · Heavy Duty mounting flange · This dock float drum meets Corps of Engineers Regulation #36 CFR Part 327 · 15 year warranty · Tank tested buoyancy ratings +0/-5%