Our custom headrest covers are available in only one size. The front is made from a speckled velvet - similar to that used for most seat cover material. The back is a stretch material. Prior to installation, with the headrest cover laying flat, they measure approximately 12 1/2" wide and 11 1/2" high. We have found that the headrest covers fist most cars. Typically, the larger the headrest the better the fit. For example, the Dodge Ram pickup truck has a large, full headrest and the cover fits quite snug. The video below is showing the headrest cover being installed on a Mazda CX-9. In some cases, those cars with non-traditional shaped headrests (like some Volvo models, for example) the headrest covers will not fit. Make sure you have clear access all the way around your headrests. If your car is a convertible make sure the seat belt guide is not attached to the headrest preventing the cover from slipping onto the headrest. If you have a late model car with a large headrest-mounted video screens this may prevent the headrest cover from fitting.