Your overactive facial muscles will be greatly reduced through using this board to relieve jaw and face tension to avoid dynamic wrinkles which can also help you to drain lymph fluid from face, making it more natural. With the design of reusable material, which makes it can be recycling use and it can gradually tighten or lift your skin. This product is made of synthetic glass material. The length of the product is 8cm, the width is 5.5cm. It is suitable for skin care and skin massage in home or travel. Item Name: Guasha Tool Material: Synthetic Size Details: 8cm x 5.5cm/3.15" x 2.17" (Approx.) Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Usage: 1.You should use some oil before use this board. 2.Then use this board hard from up to down. 3.Do not use it in air place like(windows or door). 4.Drink some water after massage 5.Do not take shower during 30 minutes 6.Do not use it in hungry. Package Includes: 3 x 1 x Guasha Stone