OFF! Clip-On Mosquito Repellent Refills are sold separately for use with OFF! Clip-On Mosquito Repellent fan units. Each box of refills contains two repellent disks. Refillable Each repellent disk provides up to 12 hours of head-to-toe protection and will work with previous and new designs of the OFF! Clip-On Mosquito Repellent device. One disk is included with the unit. Additional refills are sold separately.Use each refill within 14 days of opening. Works exclusively with OFF! Clip-On Mosquito Repellent devices to provide: No Skin Application OFF! Clip-On Mosquito Repellent provides protection without putting anything on your skin. No spray, no mess. Ease of Use Whether you clip it on, or set it next to you, protection is just a click away. The unit also contains a rotation clip for additional comfort. Odorless OFF! Clip-On Mosquito Repellent has no scent. Formulated with 31.2% Metofluthrin – provides up to 12 hours of protection against mosquitoes. Contains two repellent disks.