Features: This wheelchair anti rollovers is an electric wheelchair support wheel with a sturdy anti tilt wheels designed to provide stability and support for your wheelchair. Quality materials: Made of sturdy aluminum alloy, this electric wheelchair wheels is sturdy and can withstand daily use. Product size: The support wheel size is 20cmx5cm, and the wheel diameter is about 4cm, which is suitable for most standard electric wheelchairs. Package includes: Each package comes with a pair of reverse wheels, which is great for replacing both sides at a time or keeping a more as a spare. Easy to install: The aluminum alloy bracket and fixed tube design make it easy to install on the wheelchair, instantly enhancing stability and security. Specification: Material: aluminum alloy Size Chart: 20cmx5cm/7.87inchx1.97inch Wheel diameter: 4cm/1.57inch Package Includes: 1 Pair Anti Rollovers Wheels Note: Please allow slightly errors due to manual measurement and different monitors.