Damp-proof cable junction box made of flame-retardant, halogen-free, reinforced thermoplastic, combined with puncture membranes made of thermoplastic elastomer. The box has a high protection class and is weather and UV resistant, as well as impact resistant and unbreakable. It is best suited for extreme use or installation indoors and outdoors. It offers high resistance to vegetable and animal fats, mineral oil, diesel, weak acids, weak and strong alkalis, as well as alcohol. The permanently elastic, self-sealing lateral puncture membranes, in a patented combination with an integrated thread, allow for both direct cable assembly through the membrane and the use of cable glands without a locknut. Captive quick release cover screws close the box with only a quarter turn. The box can be fastened using a quick-assembly bracket or internal openings outside the sealing area. COMBI 308 LG.