(Farnam) Endure Sweat-Resistant Fly Spray stays active and keeps working even in wet conditions. Provides up to 14 days fly control. Protects against stable flies, horse flies, deer flies, house flies, face flies, horn flies, gnats, mosquitoes, ticks, deer ticks and lice. Endure is the only fly spray with RepeLock, an exclusive conditioner that binds to the hair shaft, locking in the fly repellency of Endure fly spray. This unique formula stays active even in wet conditions or when your horse sweats. Endure Fly Spray contains 0.15% cypermethrin, 0.20% pyrethrins and 1.60% piperonyl butoxide.