M3 sealing screws, tse tsejoang hape e le li-screw tse sa keneleng metsi kapa liboutu tsa tiiso, ke li-fasteners tse khethehileng tse etselitsoeng ho fana ka tiiso e thibelang metsi lits'ebetsong tse fapaneng. Li-screws tsena li entsoe ka ho khetheha ho thibela metsi, mongobo, le litšila tse ling ho kena libakeng tse thata, ho netefatsa botšepehi le nako e telele ea kopano.