OverBuilt to Last: Our RTIC Tough River Tubes are made from heavy gauge PVC with a double-stitched heavy-duty polyester cover that provides durability and stability. Float in Style and Comfort: The integrated backrest keeps you comfortable and the built-in drink holder fits your favorite RTIC Tumbler to keep you hydrated. Adventure on the Go: The inclusion of a speed safety valve makes for easy inflation/deflation and a carabiner and webbing rope anchor allows for easy tethering with other tubes.