Significantly improved stain removal power and coating ability! Keep your white teeth whiter for longer! This product was created for those who want professional-grade whitening at home! Dr. Koichi Shiba discovered and the world is paying attention to sodium polyphosphate, which has been increased 2.9 times more than the previous version. Furthermore, sodium metaphosphate, which focuses on stain removal power, has been added, resulting in a version upgrade. The "coating ability" that prevents stains from adhering has also been significantly improved, allowing you to keep your teeth whiter for longer! Although unopened, please understand that this item has been stored at home before purchasing. The box is slightly crushed.