The Dr. Bag Stabilizer is for rear bags that need stability or added height. It is deigned to be used by setting the rear bag directly on top. The outer edges are sewn and filled with sand to help stabilize the bottom of the bag or level out an uneven surface. Makes your bag rock solid. Be sure to choose style based on if your bag has a standard bottom or a handle bottom. Fits the Dr. Bag or Flat Top Dr. Bag. Measures Approx.: 8-1/2" L x 6-1/2" W x 1/2" Tall. Comes pre-filled with sand due to difficulty of filling. Suede colors may vary. Made in USA 100%.