Aqua Training Bag Fill Nozzle and Plug KitFill Your Heavy Bag Right The Aqua Training Bag Replacement Fill Kit is the only replacement kit for your Aqua Training Bag. It includes a hose filling nozzle and an extra plug. To make your Aqua Training Bag last longer, its crucial to fill it right. Though its mostly water, putting in air to keep it round will get rid of potential dimples and help it stand up to the force of your workouts. To do so, make sure your bag is room temperature (or warmer)