The Helio Lug from Amphenol (AKA the U-Lug)is one of the only grounding lugs listed under UL 2703 (UL Listing - QIMS.E338690 Rack Mounting Systems and Clamping Devices for Flat-plate Photovoltaic Modules and Panels)

The ULug was developed to provide benefits such as listed hardware capable of accepting 4-12 AWG solid copper conductors, does not require the use of unreliable self-tapping screws, can be used with virtually all racking systems, (0.09 inches (2 mm) to 0.25' (6.35 mm) thick), is a code compliant "first make - last break" grounding system, does not require etching or enlarging most module grounding holes, (0.16" (4mm) to 0.295" (7.5mm)) and also comes with reusable hardware for servicing without replacement

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