This is unfilled canvas bag and it can be filled upto 40-50 kgs for adult sizes and 20-30 for kid sizes Made with durable Canvas, and can be filled easily, recommended filling with used clothes You can practice, submission, lifting and throwing, take downs, strikes from ground position and other grappling techniques Back zipper and hook and loop closure. 40” and 47” are for kids and 59” and 70” are for adults.