Habitrail OVO U-Turn allows you to give a new direction to your Habitrail® setup so that you can have your hamster burrow back through a different trail. The U-Turn has air vents to improve airflow and ensure that your hamster's home is always fresh The complete line of Habitrail OVO housing and accessories is based on extensive behavioral studies of pet hamsters and is designed to help enhance their quality of life. Completely redesigned, re-tooled and reinvigorated, OVO brings even more interesting and entertaining venues in which hamsters can explore, burrow, snooze, exercise or simply chill out.