Fixman Self Amalgamating Repair Tape 19mm x 10m

Amazon

Strong black self-amalgamating rubber tape For repairs to pipes, hoses, wires & cables Insulates & waterproofs to prevent damage & injury Adheres to itself & moulds to form a rubbery, seamless, non-tacky seal Ideal for plumbing, electrical and automotive use, Manufacturer: FIXMAN

Electrical World

Non-tacky rubber tape that amalgamates itself into a strong, seamless, rubbery, waterproof and electrically insulating layer when wrapped around cables, electrical joints, hoses and pipes.