Phase Change Neck Wrap (PCNB) ties for a comfortable fit. Provides up to 3 hours of constant cooling with a segmented Phase Change Pack. A lightweight cooling option that can be worn most anywhere. Phase Change Cooling Packs deliver a constant temperature of 58 degrees Fahrenheit for up to two (2) hours. Reusable, non-toxic and non-flammable. Includes one (1) 2" x 20" segmented Phase Change Pack with six (6) 1.5" x 3" filled cooling segments. Packs do not require a freezer! Can be chilled in ice water; refrigerator or freezer optional. The cooling performance is not impacted by humidity or outside temperature. The extra set of packs is a great value! Keep in the freezer or a cooler, ready to use. Lightweight: weighs .75 lb. with pack included. Ties for a comfortable fit. Unisex and discreet design. Blue. One size fits all.