Extra Firm surface provides 36% firmer surface than the Original Density models, intended for experienced users with especially dense muscle tissue that doesn"t respond to normal massage pressure * Full size model (31x6) long enough to roll the widest part of your back and both of your legs on one pass. * Provides firm BUT FLEXIBLE surface to relieve muscular pain and tightness similar to the thumbs of a massage therapist * Stretches muscle and other soft tissues in multiple directions, breaking down "knots", increasing your flexibility, and relieving your pain. * Higher strength and tear resistance, wonderful feel, permanent retention of shape, guaranteed to outlast and outperform compared to any foam roller on the market.