BMP21 PermaSleeve Wire Marking Sleeve, 7 ft, Polyolefin, 12 to 4 Gauge. 3:1 heat-shrinking wire sleeve is ideal for labeling in harsh environments and is resistant to chemicals, grease, oil and cleaning agents. Polyolefin wire marking sleeves have a smudge-proof finish and print in black text on a white background. PermaSleeve labels provide wire identification that combines speed, ease of use and permanence for long-lasting, high quality identification. Cold resistant and flame-retardant with an operating temperature of -67 °F to 275 °F (-55 °C to 135 °C). PermaSleeve wire labels are ideal for electrical contractors, maintenance crews and industrial professionals.