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 : 9 1/8" L x 6" W x 6 5/8" H - Capacity : 0.5 Gallons *lids come in an assorment of random colors.