Sizes: Comes in either a small or large size. Gel Heel Inserts: Get a pair of posture correcting gel heel inserts. Features: These gel inserts have a shaped curved base to hold your heel in alignment as you walk, preventing inward or outward rolling to avoid back, ankle, knee, and hip pain. How To Use: Simply place the gel heel cushions into your shoes. Size: S: Length 9.2cm x width 6.5cm, and suitable for UK sizes 2.5-5; L: Length 10.2cm x width 7.5cm, and suitable for UK sizes 5-10. Gel Heel Inserts | Black | Living Social