credit card holder Free 3D print model

this is my newest 3D designe, a credit card holder tho i dont know if it works or if its secure tho its my first time designing somthing like this plus i dont have a credit card or a 3d printer to test it out. so its .at your own risk.i recomand somthing that is not too regid that can hold stres and deformation while holding his shape and maby rubber bands