Made to last: constructed from high-quality PBT, Oxford cloth, zinc alloy, and aluminum alloy. Sewing technology provides high strength, wear resistance, and a long service life. Large capacity: two-tier space lets you take two fur kids out at once. The center divider can be removed to create a single compartment for larger pets. Convenient travelling: a retractable trolley bar (telescopic height about 18.11 in) and four removable universal wheels allow smooth, bump-free movement from place to place. It behaves like a small piece of luggage in your carry-on, improving efficiency and convenience when you travel with your pet. Good breathability: breathable mesh, large casement windows that can be zipped open, curtains that can be rolled up, and ventilation holes on both sides provide airflow and visibility to prevent stuffiness. Use scenarios: - A weekend outing with two small dogs or cats, keeping them secure and comfortable while you stroll the park or run errands. - Vet visits for two pets, or a single larger pet by removing the center divider for a spacious single compartment. - Airport or train travel where you want a mobile, carry-on friendly carrier that allows easy navigation through crowds while keeping pets within reach.