Sold as a single unit with straps and wrap included in price. This boot will work on ankles knees or elbow. Ice blankets are embedded inside memory foam keeping the ice off tissue and provide even compression. Imagine a memory foam pillow with ice inside – soft yet cold. The front can be trimmed up to loop material for a perfect custom fit. It can be used wet or dry. Simply freeze or soak in ice water and apply. Straps provide light compression and can be readjusted as cold diminishes pain. It is a soft penetrating cold. The compression makes the therapy much more effective reducing swelling and speeding up the healing process. Wrap can be applied for some serious compression to push out swelling. It is recommended to be used for 15 to 20 minutes. If needed the boots can be reapplied after another 15 or twenty minutes. For all injuries see and confer with a Doctor.