A particularly breathable under rug in air mesh fabric. The mesh provides good ventilation and a wicking away function, at the same time as keeping the horse warm. Likewise, the air mesh fabric can prevent heat build-up. With a simple chest T-fastener, and 2 elastic touch tape fasteners both in the shoulder and hindquarter areas for ease of attaching to all Waldhausen Economic, Comfort and Premium outdoor rugs. This under rug is ideally suited for greatly fluctuating temperatures.