Absorbine UltraShield Sport is a sweat resistant insecticide and repellent. Stays active for up to 14 days. Absorbine UltraShield Sport protects horses and ponies from horse flies, house flies, stable flies, face flies, horn flies, deer flies, gnats and mosquitoes. Sweat and weather-resistant formula keeps working when the horse sweats and after rainfall. Apply every 14-17 days for normal fly control protection. Apply every 5-7 days for mosquito repellency. Absorbine UltraShield Sport contains 1% cypermethrin.