Scholl GelActiv Work insoles are developed to effectively absorb shock and help reduce the excessive pressure being put on your feet for a long period. Can be used for work boots, everyday shoes and trainers. They can be trimmed to fit your foot size and are easy to clean. For best results remove existing insole and replace with Scholl GelActiv insoles with the Gel side down. Replace the insoles when showing signs of wear. Every six months is recommended.