White Sierra's bug-free jersey shirt is treated with Insect Shield, an odorless invisible Insect repellent formulated with permethrin. Insect Shield repels mosquitoes, flies, chiggers, ticks, ants and midges that might carry lyme disease, West Nile virus, malaria or other insect-borne diseases. Formulated to last through 70 wash cycles. Permethrin has been successfully used in the United States as an EPA registered product since 1977, with an excellent safety record. This lightweight, travel-friendly shirt will help protect your skin from the sun, too. Details: Insect Shield bug repellent technology, UPF +30 sun protection helps block UV rays, moisture wicking technology keeps you cool and dry, fabric is pre-washed for superior softness. Center back length: 24''. Material: Cotton, Polyester.