Fast Trak Scooter TAKE YOUR SCOOTERS OUTDOORS? . Now you can! These 16" x 16" scooters with safety hand guards have oversized 4" wheels allowing you to use them outdoors or indoors. All the great scooter activities you enjoy in the gymnasium can now be enjoyed on the playground as well. Rugged enough to be used on asphalt or concrete. Each set includes 1 of each color: Blue, Green, Orange, Purple, Red and Yellow.