Habitrail OVO Den provides a cozy hangout for your hamster to hide and sleep in. It features a wide-opening door for easy access, vents for air circulation and draft prevention, and a rounded design to deter gnawing. OVO offers a variety of uniquely-designed add-ons that will increase your hamster's quality of life. The elaborate world of OVO consists of a variety main habitats, add-ons, trails, and chewable mazes that are easy to assemble, in as little as 60 seconds in some cases, thanks to the exclusive Lock Connectors, that allow quick and easy connections. Built on Habitrail's long-standing reputation for innovative hamster habitat designs, OVO provides a variety of amazing and entertaining living spaces for hamsters. 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.