Heel lifts can be used for more than just correcting leg-length discrepancy. Used in rehabilitation, heel lifts raise the heel for lower-limb swing-through and improved gait. Used bilaterally, heel lifts can help relieve stretch and strain on the Achilles tendon and calf musculature in conditions such as Achilles tendonitis, plantar fasciitis, or heel spurs. Pack of 2 is 2 lifts, one for each foot. Single lift is for 1 foot