??4mm Heat skrink tube 300mm long - DIY Essential
This shrink tube can be shrink to half of its diameter. For example, 4mm diameter can be shrink to 2mm.
Use a lighter or a hot air gun to heat up the shrink tube with a up and down movement to heat up the whole tube evenly. Do not heat up the tube in one spot this will burn the tube.
4.0mm is suitable for 3.5mm banana plug