Off! Clip-on Mosquito Repellent with 4 Refills (Includes Batteries) Black 2013 Model Mosquito protection you don't spray on! Contains: 1 repellent fan unit, 4 refills, 2 AA batteries. Great for backyard, gardening, watching sports, at the beach, camping, at the park. Each refill provides head-to-toe protection for up to 12 hours. Portable Clip-On Outdoor Mosquito protection.