Thanks for choosing our ZENSTYLE bird cage. Our 52'' large bird cage is made of high quality material. The metal welded frame and pp tray make this cage a durable and safety pet home. The front door has sturdy lock which can prevent your birds from opening the door. It can keep the bird safe and securiy. This cage includes 4 PP universal wheels which can swivel 360°. It is convenient to move this cage to any direction smoothly. The draw-out tray with water-proof paint can be removed and cleaned with water. A grate between birds and the tray can avoid your pets walking directly on their droppings, which ensures both your pets'hygiene and the tidiness of the cage.