The Saddle Anchor Bag is made from a heavy-duty, woven polyester and is designed to anchor a soccer goal onto any type of surface, indoors or out. To properly install this anchor bag system simply: 1.) Pour sand (not included) into both sides of the bag 2.) Secure sand in bag by completely zippering bag closed 3.) Place the bags in the back corners of the base frame (this location allows for maximum counter balance) A key feature of this anchor bag is the amount of space between the handle and the bag – this space allows the net to be properly clipped into place without sacrificing any of the security the bags are intended to provide. Kwik Goal recommends six (6) of the Saddle Anchor Bags to properly anchor one full-sized 8' x 24' Kwik Goal soccer goal.