This is a good quality heat shrink. We have tested it ourself in future electronics Egypt (Arduino Egypt) and we found that it can withstand lighter fire without crack for really a long time.

• Diameter:                                  6mm
• Diameter After Shrink:             3mm

Material properties

• Material:                                      Flexible Flame Retardant & Cross-Linked Polyolefin
• Shrink Temperature:                  90°C
• Operating Temperature:          -55°C ~ 125°C
• Radial Shrinkage:                      50% Min
• Longitudinal Shrinkage:           5 % Max
• Tensile Strength:                       ≥10.4Mpa
• Flammability:                             VW-1 (Vertical Flame Test Pass)

Applications

• Insulation Protection and Bundling of Wire Terminals and Connectors
• Insulation Protection of Soldering Points
•  Capsulating of Electronic Components
• Anticorrosion of Metal Components
•  Color Coding