These puncture resistant insoles are made from a super strong fabric that resists nail punctures and more. Lightweight and easy to wear in your work shoes, these insoles will never contribute to foot fatigue or weigh you down. Their flexibility makes it easy to use with other comfort insoles without compromising your foot’s natural movement. Contains thermal insulation properties that help to keep your feet warm in the cold or cool in the heat. Will not activate a metal detector. Meet EN,CSA,ASTM standard.