Its very convenient for you to put on or take off the pet clothes. Sizing for each dog is unique. You’d better to measure your pet precisely with a flexible tape measure to ensure the best fit. Size Chart: Size XS: (neck 9.5"chest 11"-15" Fit Cat);Size S: (neck 11"chest 15"-17.7" Fit Cat or Small Dog);Size M: (neck 13"chest 17"-19" Fit Cat or Small Dog);Size L: (neck 15"chest 19"-21" Fit Small Dog).Attention: 1 x Pet costumes and 1 x Hat. If you meet any problems on this product you can feel free to contact us.