This carrier bag is multifunctional, as it can be carried in different ways, quality bag and very spacious. Very spacious interior, accepted under the seat of most airplanes (check with the airline company) Suitable for very small, small, medium, intermediate and large dogs. (see size). Characteristics: - Carrier with shoulder strap - Backpack - Bag that can be inserted in the trolley (trolley not included) - Closed or open carrier - Foldable for storage, cover included - Comfortable for back and shoulder - Removable strap - Ideal for travel or trekking transportation The trolley on the pictures is not included, the color may differ as well. S (15 1/2" - 17") Width x 11" Depth x 13 3/4" Height up to 26 lbs. L (18 1/4" - 21") Width x 14" Depth x 13 3/4" Height up to 32 lbs.