Use 3:1 medium wall adhesive lined heat shrinkable tubing for direct burial of heavy duty electrical cable, where environmental protection is necessary. Tubing is supplied with an adhesive layer, adding a water tight seal to the strain relief the tubing provides. When exposed to heat (usually a bit lower than the activation temperature of the heat shrink), the inner layer begins to flow (just like a hot melt glue).
2 Pcs 1/2 inch (Diameter) Heat Shrink Tubing, 3:1 Adhesive-Lined Large Heat Wire Shrinkable Tube by MILAPEAK (4 Feet, Black & Re
3M Heat Shrink Tubing
Safety and Environmental Protection: Purple-fox heat-shrinkable tubes are UL and CSA certified, RoHS compliant, free of formaldehyde (HCHO), heavy
2 Inch Heat Shrink Tubing 3:1 Adhesive-Lined Heat Shrinkable Tube Waterproof Insulation Sealing DIY
3M Heat Shrink Thin-Wall Flexible Polyolefin Adhesive-Lined Tubing
HellermannTyton 318-60152 Heat Shrink Tubing, 4' Long Stick, Adhesive Lined, 3:1 Shrink Ratio, 1/4, 6.0/2.0 Dia, PO, Black, 15/pkg
1/16 Heat Shrink Tubing Low Temperature 2:1 Ratio | 500' Spool | BuyHeatShrink
Heat Shrink Tube - Dual Wall 1/4 - 6 Inch Lengths
AIRIC 5/8 inch Heat Shrink Tubing 3:1 Marine Grade Shrinking Cable
Adhesive Lined Heavy Wall Heat Shrink Tubing
3:1 Heat Shrink Tubing Dual wall Adhesive Lined Waterproof - Temu