Heavy duty cushioning: features - hard-wearing heavy duty insoles; durable cushioning materials; quality construction; specially designed for heavy workloads; moulded nyloflex shell stabilises foot; provides all-day-long comfort & support; deep heel cup & arch support help anchor foot; dense ultra bound foam for more custom fit; posted shell to help correct foot posture; helps alleviate heel spur & heel strike pain; distributes body weight evenly over foot; relieves stress from spine, knees, ankles & foot; odour-inhibiting with anti-bacterial top cover.