A kick scooter, push scooter or scooter is a human-powered land vehicle with a handlebar, deck and wheels that is propelled by a rider pushing off the ground. The most common scooters today have two hard small wheels, are made primarily of aluminium and fold for convenience. Some kick scooters that are made for younger children have 3 or 4 wheels and are made of plastic or do not fold. High-performance racing scooters made for adults resemble the old "penny-farthing" with a much larger wheel in front.