The Stop-A-Flat Puncture Proof Bicycle Inner Tube is specifically designed for 20-inch wheels and features a Presta valve type. Made of foam material in a vibrant yellow color, this tube is ideal for cyclists looking for a durable and puncture-resistant option for their cycling tire. The 20 X 2.125 style ensures a proper fit for your bicycle, providing peace of mind during your rides knowing that you are protected from unexpected punctures.