Gravity-Tube™ Ultimate ANCHOR System! The BEST Way To Anchor: For all types of outdoor canopies! A revolutionary new anchoring solution that utilizes renewable Gravity Pull-Down Technology to create rock solid stability in wind. Kit Includes: (4) Heavy Duty PVC Tubes and Boat Straps: The adaptive tubes are suspended from each upper corner leg with boat straps, sets up quickly. Gravity-Tubes totally maximize weight and anchoring effectiveness on all types of terrain including, sand, hardpan cement and asphalt applications. Just fill the heavy duty PVC tubes with sand, dirt rock or even water if available. As many users know, even the slightest wind can lift a canopy in a blink-of-an eye, causing damage or total destruction to the frame. This is the perfect anchor solution for any and all outdoor applications. * Fill each Tube with Sand, Rock or Water * (4) Tubes with Attaching Boat Straps * Durable Heavy Duty PVC Construction * Adapts to All Types of Free Standing Canopies * Adds Up to 180 Pounds of Leveraged Weight