This cage bank boasts all the same features as the MCL-509 with the added bonus of a strong, durable 8mm thick transparent acrylic front door. This cage has been proven to be an asset for any facility that cares for animals with cardiovascular or respiratory issues. This proven design safely, reliably, and conveniently allows pets to rest in the oxygen levels prescribed to help them. You need only to adjust your flow meter and allow oxygen into the unit. Predrilled ventilation holes on both the back wall and front door along with an installed thermometer and hygrometer will help give you peace of mind as your pets rest by accurately displaying temperature and humidity levels in the cage.