What are the RX Metatarsal pad / ball of foot cushions? Featuring an exclusive cushioned layer for maximum comfort the RX cushions have been specially designed to absorb impact and shock to the ball of the foot. When can I use the RX Metatarsal pad / ball of foot cushions? Suitable for use in casual and athletic shoes the RX ball of foot cushions can be used to provide maximum comfort during a range of outdoor and sporting activities such as walking and running. How do the RX Metatarsal pad / ball of foot cushions work? The RX metatarsal pad / ball of foot cushions feature an exclusive cushioned layer to absorb shock and impact ensuring of maximum comfort as well as providing support and stability to the ball of the foot. These ball of foot cushions also feature a four-way stretch fabric with an antimicrobial layer to help prevent blisters and control odour. What size do I need? To fit UK shoe size: - Small 5-7 - Medium 8-10 - Large 11-14