the design and functionality of this dog stroller is basic and durable. there is no internal tether/leash to ensure your pup stays inside. there are no external pockets or storage for your own items. very bare bones and does what it needs, purely. got this for $90 when it was on sale; which is nice compared to most of the $150-300 large breed strollers. this is made for one large/x-large dog or multiple medium/small dogs. my dog is 48 lb large breed. sitting in the stroller is awkward for her given her size so she normally lies down. assembly was a breeze, which was just putting the wheels on permanently and propping up the frame to secure the handle bar into place. the handle has to be completely detached to collapse the frame, so it isn't the most convenient nor portable for on the go everyday use and keeping it in the car. the wheels are static and only the frame (D-shaped side walls) collapse inward. all the zippers are smooth and durable. the wheels are hard plastic and are great for walking/jogging paved paths. my 12 year old chow rescue has lost her endurance now that she is a senior pup. this is a great way for me to get more steps in while also bringing my senior dog for the fresh smells and sights.