Features: EASY TO USE: assembly required, just place the chairs legs in the correct position. Suitable for chairs with 4 legs (round, square and curved legs). Stretchable: legs can be rotated at any , and the length can be adjusted by stretching, which is suitable for most chairs. Anti-skid: There are anti-skid on both sides of the bottom, which is stable and safe to use and will not scratch the floor. Small and Lightweight: Easily for storage and travel. It is suitable for helping adults with knee pain, joint pain, and hip problems to sit and stand on their own, as well as those who need for extra help, such as children and the elderly. Specifications: ABS Size Before Stretching: Approx. 32.6x32.6x16.2cm/12.83x12.83x6.38inch Note: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1x Chair Booster