The small size fits perfectly in a small to midsized SUV while the large fits great in a mid to full size SUV. The gray and tan colors compliment most interior automobiles. The outside bolster isMade from 600 denier nylon with a water,resistant backing. the removable cushion isMade from soft and luxurious microfleece. Cushion has tufting to keep the premium polyfil in place. the bottom of the bed has a "stay put" non-slip fabric to keep the bed in place. Easy machine wash care. water,resistant bolster cuddle in comfort Stay put bottom for stability Easy wash and care Sleeping Dimensions: 17" x 31"