Support your body's efficient, optimal position during exercise with the OPTP PRO-ROLLER Arch. Use the versatile Arch to improve posture on a foam roller, to enhance Pilates routines, to increase the instability of a foam roller, as a positioning tool, block or cushion, and so much more. When placed across the top of a PRO-ROLLER (or any 6" diameter foam roller), the Arch helps prevent hyperextension of the cervical spine. When multiple Arches are placed under a foam roller, it raises the center of gravity, making it less stable. Its shape is also ideal for a spacer between the knees or a cushion under them. Constructed from soft, durable EVA foam. Measures 5.5" H x 10.5" W x 4.75" diameter; raises head 2.25" when placed on a foam roller. Includes instructional poster.