Steel frame * The front and back mesh doors allow for maximum ventilation * The doors have two layers; The Outer layer is transparent PE, inner is mesh * Large back wheels which have a quick release design for easy storage * Sporty Bicycle trailer designed for dogs up to 120 lbs * Very stable and durable frame * Secure Bicycle hitch arm with axle-mounted hitches. * Easy-access main compartment with front and rear zippers. * The material is very comfortable and easy to clean. * Includes a flag and two reflective lights * Cannot be used as stroller.