M16878/15 NEMA HP 5 Type LL is a cross-linked polyethylene (XLPE) insulated general purpose electronic hook-up wire. Commonly used in switchboards, panel boards and distribution boards. This specification is currently referred to as NEMA HP5 Type LL. MIL-DTL-16878/15 temperature rating is 55°C to 125°C and a voltage rating of either 600 or 1000 volts.