Just unzip and see for yourself. Finally, you have the outside covering. It can be vinyl, leather or fabric. Vinyl is usually the least expensive, is quite durable and cleans easily. Since it is not porous, it tends to be cold in winter and hot in summer.
Leather can be very expensive depending on the quality of the hide.
Fabric offers the greatest variety. Initially you may be drawn to the color and pattern that is most appealing. Then you need to check the feel of the fabric. Durability is the next important subject. Quality fabric should be tightly woven.