The bags may be used two ways. First it can be made to the size of the dulcimer so that it can fit inside of the hard case as added protection. The dimensions would need to be given at time of placing the order. Second, it can be made larger for the dulcimer to slide into and also have a strap attached to the bag so that you can carry it on your shoulder instead of having a hard case for transporting your dulcimer. I hope this helps. Thanks for the input Folkfan.