Our patent-pending & cooling Guard Locker™ - Neck Gaiter has 2 pockets. Use the cinch cord to customize the fit - one size fits all adults & children over 12. * Front Pocket: Fit a mask or filter. Protect against dust, wind, mosquitoes, the sun, harmful particles or the cold.  * Side Pocket: Stash keys, ID, or extra mask in the side zipper. * Uses: Cooling sun protection. Shopping, motorcycling, camping, running, traveling, biking, hiking, skiing & more!  * Fabric: Machine-washable & dry-wicking. * Materials: 77% Polyester + 23% Elastane * 4 PCS: 1 Guard Locker + (3) 2.5 Particulate Matter, 5 Layer Carbon Filters 3 Filters Included per Guard Locker The filter has one carbon layer sandwiched between spun-bond fabric. They are meant to effectively last 24 consecutive hours which tends to last most people 4-7 days.