Black Heat Shrink Tubing 2:1, 12.7mm Dia x 1.2m, 

sold in 5M lengths but can do continuous if need more than 5M
Sleeve Diameter12.7mm
Shrunk Diameter6.4mm
ColourBlack
Sleeve TypeHeat Shrink
Adhesive LinedNo
Shrink Ratio2:1
Sleeve Length1.2 m
MaterialPolyolefin
Minimum Operating Temperature-55°C
Maximum Operating Temperature+135°C
Flame RetardantNo
Dielectric Strength500V/mm
Halogen FreeNo
AngleStraight