GLI 55-0000TY-BK Typhoon Inground Pool Solar Reel Resin System Base Kit Typhoon reel system is made of heavy duty resins that take a beating and look great The large wheel design rolls over virtually any surface for easy roll away storage The crank mechanism is engineered with pinch roller bearings to provide smooth, effortless cover roll-up with crank handle Tube kit are pre-drilled for easy installation It is recommended to use 4-inch tube kit for pool 600-square feet and larger or when using thicker mil solar blankets