They are Grade B brand new. They are UL listed for Grid Tie installation. What is grade B though? Grade B panels have visual defects that do not affect performance. Cell spacing could be off, could be a scratch on the frame, etc.In the video you'll see some silicone on this particular panel that is on the glass but comes off with my fingernail. Model: Heliene 132HC M10 SL Monofacial Module Electrical Specs: 490 Watt 46 Voc 38.88 Vmp 13.3 Isc 12.58 Imp Max Series Fuse 30A Physical Specs: Cell type is Mono-crystalline PERC 2094 x 1134 x 35 mm (82.44 x 44.65 x 1.38 inch) 27 kg (59.5 lbs) MC-4 Male and Female connectors.