RiteChoice Dog Agility Tunnel Bags hold your Dog Agility Tunnels securely in place on all surfaces without staking. It's extremely important to stabilize your tunnel for safety and the most efficient use. These bags can be used with any RiteChoice Tunnel on grass, turf, matting, sand or any hard surface. Just fill the bags with sand, hang over the top of your tunnel like saddlebags & you’re set! Each sandbag will comfortably hold approximately 30 - 35 pounds of sand. Used in both indoor or outdoor applications. Includes 2 Bags that connect together in the center with a velcro closure. Sand not included. We recommend 2-3 sets of tunnel bags per tunnel depending on length of tunnel.