Wool is a 3-dimensional protective fiber that forms pockets of air quickly wicking away moisture. Wool's natural springiness relieves pressure points and provides soothing support and naturally soothes muscle aches. Wool absorbs and releases heat buildup and naturally holds its shape, doesn't attract dirt, cleans easily and is extremely durable. EuroTech hygroscopic wool blend pads readily absorb up to 1/3 of its weight in moisture. Thermal regulating properties naturally pull heat away from your horse's back. Size medium, fits saddles 16.5" to 18".