The 83251621 by Lapp Kabel is a heat shrink sleeve made from a 4.8 mm diameter, blue colored polyolefine. It has a 2:1 ratio of shrinkage, and it has no need for any gluing, making installation and re-entry easier. The heat-shrink sleeve has a shrink temperature of 80°C and a thin-wall design for an increased insulation. It is perfect for industrial, automotive, and home usage.