1. Specially for acrylic, crystal, and other gifts with inside holes, curved edge, it can solve many common prooblems that the other machines can not do.2. Specially for the materials that with more uneven surface. It fit for all kinds of thick acrlic polishing. This machine not only can work indoor, it can also works outdoor.3. This polishing machine fit for the jewelry factory, gold shop,and welding, casting, quenching of other fields, all kinds metals welding, many high temeprature materials test and so on.