Zilla Deluxe Critter Cage® Enclosures 40 BreederOur best selling Critter Cages with a sliding screen top are now available with lockable feeding door. This new design provides a comfortable, safe enclosure for pets and minimizes the chance of escape during feeding time. The front sliding, metal screen contains a feeding door with locking pin that is approximately 6. 5" x 4" as well as breakouts designed for hang on water bottles and electrical accessory cords.