Designed to be used with the Innorack® IVC Rat & Innorack® IVC Tall Rat. Used together with non-XL Innocage® lids. Universal Euro III Type Long, sized for 2 rats. 100% PET plastic. BPA-Free. Recyclable. Interior dimensions: 141 in² floor space (909.7 cm² floor space) Outside dimensions: 17"L x 13.4"W (maximum) (43.2 x 34.0 cm (maximum)) Height and living space varies by lid type.