HPN on NEC / UL (USA)-järjestelmän kaapelin tyyppimerkintä: H = Heater cord (UNVERIFIED); P = Parallel construction (UNVERIFIED); N = Neoprene insulation (UNVERIFIED); HPN = Heater cord, parallel, neoprene (UNVERIFIED expansion). 300 V, 90 C (UNVERIFIED). UL 62; NEC Table 400.4.