It features SUPER SOFT 100% Thermal Cotton. It also features an OPEN TAIL END for quick potty breaks. These pajamas have a fantastic stretch which makes it very comfortable to wear and easy to put on. We embroidered the BOTTOM with 'Sweet Dreams.' The following measurements are the DIMENSIONS OF THE ACTUAL PRODUCTt, not of the pet they fit DIMENSION X-Small Back Length: 8' Chest: 10-13' (Most Important) Neck: 7-10'