The Curve Ball is a stationary foam roller great at deep tissue muscle massage. This patent-pending inventive tool offers stable and controlled deep muscle massage. The orange, flat base is grippy, which means it won?t slide around. It stays in one place allowing for sustained traction on the muscle. Curved massage surface provides targeted muscle care and relief of minor muscle aches and soreness. Use your weight as leverage and let the tool do the work! Check out our book "Happy Muscles" to help identify muscle knots/trigger points our tools can help with.