All Kritter Keepers have well-ventilated lids in assorted colors and may be used as space-saving aquariums or insect havens but are also ideal for use as small animal keepers kritter totes terrariums or nurseries. Rectangular Kritter Keepers have self-locking lids with hinged viewer / feeder windows an airline access hole and an attachment hole (except Mini and Small sizes). The Mini Small and Medium sizes have carrying handles for easy transport. Size : 7 1/8 L x 4 3/8 W x 5 1/2 H Capacity : 1.69 Quart