The inner and outer hoop snap together to hold the fabric firmly in place, meaning you won't have to readjust as often since it won't slip like it does with wooden hoops of the same economical price point.  We love stitching using these plastic hoops, but if you plan on framing your project, then transferring the finished embroidery to a wooden hoop is a good choice! It's great to have both types of hoops in your tool kit.