The hot-melt inner adhesive provides a watertight seal when properly overlapped - the solder ring connects the two conductors during the shrink and melt process. An advantage of the transparent version is that you can see the wrapped object. The application is very simple: strip the cables and insert them into the connector from both sides until the stripped cable ends overlap or twist under the solder ring. Evenly heat to the melting temperature of the solder until it melts - preferably with a hot air gun or hot air blower - and you're done. The maximum current is limited by the cross-section of the conductor of the cable used, its conductor material, and the quality of the solder joint. Special feature: with shrink tubing.