Hard maple wooden massage balls roll out tightness and promote flexibility in arch and forefoot, alleviating conditions of plantar fasciitis   How it Works By rolling the bottom of your feet on the Plantar Massage Balls, targeted compression is applied to the deep tissues, expediting the healing process. Two sizes are available, providing an option to target the arch, heel or metatarsal area Includes Two  Medium (1.5" diameter) and two Small (1" diameter) massage balls