What are the Gel Heel Cups? Featuring a dual layer construction & shock absorbing properties, these durable heel cups provide superior support & all-day comfort for your feet. When can I use the Gel Heel Cups? Use the gel heel cups to provide relief from heel pain, Plantar fasciitis, heel spur, knee & ankle pain as well as back pain. The heel cups are ideal for prolonged periods of standing, as well as for sporting activities. How do the Gel Heel Cups work? The gel heel cups have a dual density, soft gel silicone construction that absorbs shock on heel impact, & provides even pressure distribution for effective relief from heel pain, ankle pain, knee pain & back pain. Hypoallergenic, non-toxic, non-flammable & odour free, these gel heel cups can easily be washed & transferred between footwear. What size do I need? Men: UK 3-8 Women: UK 5-6.5