If you choose to buy the Cocoon as a pet bike basket, the basket comes with a KLICKfix adapter for standard size handle bars (.87-1.02 inches). If you have a non-standard size handle bars, KLICKfix.com has other adapters and accessories available on their site. The pet bike basket also has a long carry strap that means you can use the Cocoon as a shoulder bag and a mesh dome.
If you choose to buy the Cocoon as a Car Seat, the basket has a leash set that comes with it to tether your dog inside. The car seat also comes with a shoulder strap and a mesh dome. If you want the Cocoon to be more of a booster seat for your pet, an additional leash set must be purchased. Then you can secure the basket around the headrest of your car.