4 wheels. It stands upright when you walk, or you can tilt it like you're walking up a flight of stairs. Side pockets are large, not translucent, plus a deep zippered front pocket! The small zipped back pocket is enough for my cell phone! The care is already set, just put it on and start rolling! You can even detach it from the trolley and use the trolley for other things as well as carry your bag. And it's durable and water-resistant! I love it!