The lightweight Kool Max Poncho Vest (KMV) efficiently and effectively cools the body in any environment, under or over clothes. Reusable, non-toxic, water-based cooling packs provide constant cooling for up to 4 hours. The Poncho Vest is one size fits all and includes 10 Kool Max Packs. The 4.5" x 6" packs fit into insulated pockets inside the vest. The pockets have a comfortable all-cotton fabric to protect the skin and an insulated outer composite fabric to direct the cooling energy toward the body. The location of desired cooling is easily controlled by which pack pockets are used. Place the packs in the freezer until they are frozen hard; for best results, store in the freezer, so they're ready when you are! Simple and unisex design. Adjustable at the chest, waist, and shoulders. Lightweight vest weighs 3.7 lbs. to 5.5 lbs. Weight may be adjusted by varying the number of cooling packs used. This is an excellent vest for wearing under uniforms or protective clothing. Available in Blue or Khaki. Kool Max Big & Tall Poncho Vest is also available.