Helios H4 RADSOK® Solar Connectors Amphenol Industrial RADSOK® Helios H4 Solar Connectors provide solutions for all segments of the solar electric system while featuring a 52A rating. The H4 connectors provide efficient, low-loss power transfer through precision machined contacts utilizing RADSOK technology. The H4 Series offers high reliability for both thin-film and crystalline silicon technologies. A quick, easy, and safe NEC 2008-compliant locking system with secure snap-lock mating makes the H4 one of the most advanced solar connectors available. The Helios H4 series meets NEC 2008 standards as-is, with no additional components needed. With a 25-year UV and ozone resistance, the connectors meet waterproof IP67 standards and withstand hydrolysis, oil, chemicals, abrasion, corrosion, and extreme temperature.