?Upgraded Design?Unlike other hamster cages fixed by silicone rings, we strengthened the robustness of the cage. It won't fall apart even when moved around. There are vents on the top of the cage, which ensures air circulation and removes odors inside. There's also an additional viewing window on the liftable roof, convenient to open and providing more observing angles. ?Premium Quality?Constructed with firm and high-density natural wood finished with corrosion resistant and waterproof coating. The material of the windows are transparent acrylic sheets, so that you can always have a clear view to observe the activities of the hamsters. It also comes with a clear sheet to place on the bottom of the cage, it avoids moisture and makes cleaning so much eaiser!