Camp 20" Alloy 16 Speed Folding Bike Disc Brake Thunderbolt 20 inch folding bike with shimano Altus 16 speed rear derailleur Alloy hub seal bearing and anodized color,cassette 12-32T,dual disc brake.When you riding ,more comfortable and smooth Easy to fold with magnet,perfect for taking on a bus or train on your commute or stashing in your apartment The foldable bike frame with small rubber protector to avoid scrath the paint when fold the bike With adjustable kickstand,and fender,rear cargo rack