The Professional 3:1 Adhesive-Lined Shrink Tubing Kit by Wirefy includes 130 pieces of black and white heat shrink tubing with a 3:1 ratio. The tubing is 3.5 inches long and has an outside diameter of 19 millimeters, suitable for electrical equipment and supplies. The self-adhesive installation method makes it easy to use, and the UL certification ensures quality. With a maximum pressure of 4 bars and a voltage of 600 volts (AC), this kit is perfect for various industrial and office applications requiring reliable wire and cable management.