Cando Round Foam Roller 6 x36 Extra Firm Back Body Massagers output level ≤125+3dB Max OSPL90 Hip Kits output level ≤125+3dB Max OSPL90 ≤125+3dB Average OSPL90 118±3dB Max Gain 45±5dB FOG50 HFA Avg * Included wireless telemetric heart rate chest strap will help you stay within your target heart rate zone for an efficient workout Black composite foam roller * Perfect for positioning balance postural and muscle re education spinal stabilization body awareness and coordination and ranging and strengthening activities * Round rollers offer progressive exercise sequences user can move from an easier (smaller diameter) to a more difficult (larger diameter) roller * The ethefoam rolls are strong enough to be used by large adults and active children