2. According to the production and installation materials can be divided into thermal shrinkage (the most commonly used kind), dry cladding type, epoxy resin pouring type and cold shrinkage type.

3. According to the core material, it can be divided into copper core power cable head and aluminum core power cable head.

4. According to the joint material, it can be divided into plastic cable joint and metal cable joint. The metal cable joint is divided into porous metal cable waterproof joint, anti-bending metal cable joint, double locking metal cable waterproof joint, plastic hose cable joint, metal hose cable joint and so on.

Its main function is to make the line unblocked, keep the cable sealed, and ensure the insulation grade of the cable junction, so that it can run safely and reliably. If the seal is not good, not only will oil leak cause oil-soaked paper dry, and moisture will also invade the cable interior, so that the paper insulation performance decline.