Trigger Point Eco Grid 13'' - TanMade with 30% renewable, biobased materials, in addition to EVA foam and a recycled plastic core Three dimensional surface allows tissue to aerate while you roll, promoting the flow of blood and oxygen, the nutrients needed to repair muscles Proprietary Distro density zones replicate the feeling of a massage therapist's hands Hard, hollow core hand wrapped in biobased materials and EVA foam makes it firmer than traditional foam rollers Superior