1. Material: aviation equipment titanium alloys2. Rear wheels with quick-release device for easy transport and store3. Rear wheels have 2 ranks of adjustable button4. Front wheels have 3 ranks of adjustable button5. Double cross, can be folded6. Detachable and swing-away armrests7. Footrest for aluminum bending welding can protect childrens foot from being collided8. Rear wheel: 20 inch with quick-release9. Covers small space after folding for convenient family traveling10. Backrest is detachable11. Thickened seat cushion and sponge cushion12. Backrest can adjust to the best state according to individual demand