Pratley no. 2 with pratley connectors or break out box with Pratley connectors

[Deleted member 26818]

You can get different grades of heat shrink.
Though using heat shrink to cover screw connector blocks would negate the MF properties of the joint.

 

[westward10]

Most heat shrink is pretty poor for insulation/protection. I tend to use two layers of adhesive lined heat shrink some of which can be a few mill thick.

 

[telectrix]

Wiska SH525W 5 Core 6-25mm Cable Insulated Joint with 5 Pole Terminal Block IP68 0.6/1KV | City Plumbing Supplies - https://www.cityplumbing.co.uk/Wiska-SH525W-5-Core-6-25mm-Cable-Insulated-Joint-with-5-Pole-Terminal-Block-IP68-0-6-1KV/p/228242