AIRfeet Outdoor O2 Insoles KS7+ The splint creates a dynamic The splint creates a dynamic springboard action under the big toe joint or first metatarsal using the tension band concept to distribute force across the length of the entire metatarsal instead of directly on the joint during the toe off segment of walking or running (propulsion) These socks feature medical grade graduated compression (15 20mmHg) to help push blood through your legs and feet and help prevent venous issues related to long term sitting or standing The AIRfeet Outdoor O2 massaging insoles are designed to ergonomically dispense an impacting energy Place the insole right on top of the existing insole with no need to tear your shoes apart