Cable sockets JB12 and WC16 are used to simplify the wiring of electrical installations or central heating systems, for example. Pre-assigned joint terminals allow better testing of the control paths and wiring and allow faults to be detected and rectified more quickly. Junction box JB12 features 12 large terminals, nine possible cable inlets, a large voltage warning sign and strain relief clamps and thereby guarantees professional, safe and compliant installation and troubleshooting. Junction box WC16 features 16 large terminals, five possible cable inlets and a large voltage warning sign. The terminal box was specially designed for use with a 2-way or 3-way central heating system. For a better overview of the incoming and outgoing cables, the contents include cable marker stickers that can be attached to the cables of various control components for clear identification.