(Fly Armor) Fly Armor attaches to horse gear to repel flies, gnats and mosquitoes. Fly Armor Poll Band holds 2 replaceable Citronella oil inserts (included) for up to four weeks of protection. Replace the inserts when they lose their effectiveness. Three hook-and-loop attachments on back of band allow you to fasten to your bridle, halter, martingale or reins. Vaporguard backing provides a barrier between poll band and your horse. 1 1/2" x 12".