3M Heat Shrink Heatshrink + adhesive 620757 - 3M MDT-A12/3, The 3M MDT-A12/3 heatshrink is a black, adhesive-lined tubing designed for secure sealing and protection. It offers a shrinkage ratio of 4:1, transitioning from 12 mm to 3 mm, and is suitable for cable insulation and strain relief. This 1 m long heatshrink is typically used for electrical repairs and reinforcement. 3M MDT-A12/3 MDT-A Heatshrink + Adhesive Black 12mm-3mm 1m 4:1 Shrinkage