Thank you for viewing. I purchased this from the official online store last November. Unfortunately, I haven't had the opportunity to use it, so I'm offering it to someone who will. Since the feather-shaped Gua Sha is currently unavailable, please consider this if you are looking for one. [Gua Sha made of 100% natural obsidian] With four touchpoint surfaces and a flat surface, this Gua Sha brings the effects of "flowing, pressing, and loosening," promoting lymphatic flow in the face and body, and is expected to have various effects such as a smaller face, improved blood circulation, and reduced swelling. Obsidian, the raw material for the black Gua Sha, is a glassy power stone formed by the rapid cooling of volcanic lava. Born from a volcano, it has excellent heat retention properties and is also used as a hot stone for massage. ■ Effective Usage: Before use, warm it in hot water at around 43 degrees Celsius for 2-3 minutes, and use it in conjunction with a "hot stone mask" for more supple and beautiful skin.