The Alternative to Night Splint. Treat your plantar fasciitis 24 hours a day with this Orthotics And Beyond exclusive savings pack Aircast AirHeel provides daytime, active pain relief for plantar fasciitis, Achilles tendonitis, and heel pain Thermoskin Plantar FXT provides a user adjustable stretch to the plantar fascia to alleviate pain from plantar fasciitis The AirHeel sleeve is a universal fit for both the right and left feet. Order by Women's and Men's shoe size. The Plantar FXT is universally designed to fit both the right and left feet. Order by Women's and Men's shoe size.