The NRS Rodeo Split Stern Flotation fits in the back of your boat to stop your boat from filling with water in the event of a swim. The less water in your boat the easier it will be to get to shore. Don't lose your boat! These bags come with a lifetime warranty. The the Rodeo size fits in large freestyle boats and free running boats.To determine the correct size of float bag for your boat, measure the inside compartment and order a bag that is slightly larger in dimensions to fill the space in your boat completely.