The Brother T-8422D is a twin needle direct drive lockstitcher with thread trimmer Great Needle Penetration Force Powerful 550W motor outputs large amounts of torque even at slow speeds so that strong needle penetration force can be obtained. This allows accurate sewing of heavy materials and joints. If the needle penetration resistance increases, such as when sewing heavy materials and materials with joints, vibration control (intermittent impact) automatically increases the penetration force.(Patent pending)