This abdominal wheel with automatic rebound and elbow support is scientifically designed for efficient workout. Features: Multi-function 2-in-1: Elbow support abdominal wheel and plank support 2-in-1 for more efficient workout. Automatic Rebound: Built-in brake system, steel plate rebound is more stable, making training simpler. Wide Double Wheels: Stable double wheels with wide wheels are slip-resistant and wear-resistant, safer. Intelligent Timing: With a timer, making your training more planned. Easy Installation: Simple parts, installation is not laborious. Specifications: Color: Orange/Grey/Blue (Optional) Material: ABS, PVC Wheel Width: 10cm / 3.9in Package Size: 44*22.5*10.5cm / 17.3*8.9*4.1in Package Weight: 1500g / 52.9oz Package List: 1* Elbow Support Abdominal Wheel 1* Timer 1* Instruction Manual