Extra Firm vs Firm - DaVinci Extra Firm for more intense tension, DaVinci firm for less intense. Exercise caution and do use for longer than 30 seconds. Davinci Tool (Red) -USA Made- Hard Rubber Neck Tension Relief & Pressure Point Massage Tool - Occipital Release Tool - Cervical Traction Device- Suboccipital Release Device - Neck Stretcher.
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