I use one case for all my harps. Having cases for each of them is just inconvenient for me. Designed this to be used with rubber cord to keep it tight. The design of the guard is suitable for all harps with max 20mm long trigger. Use a 3mm rubber cord. if there is nothing to attach the rubber loop to, use provided clips. There is two sizes at the moment. For 4mm and 5.5mm thick frames. *Update 2020-01-03: Added a guard with the Oberton Pro logo. For those who can't handle my logo :D*