Soomloom Mute Ab Wheel Roller Abdominal Trainer with Knee Mat Wheel Diameter: 5.90 inches Ab Wheel Total Length: 11.80 inches Weight: 1.4 pounds Material: Hand Grip: High-density, tear-resistant sponge Wheel:mute,no harm to floor board Eva Wheel Hub:Abs Capacity 500 lb. Tone and strengthen the abs, assembly required Double wheel for smooth functionality and balance Comfortable to use with foam hand grips and knee pad