It is a 40-feet long UL certified 12AWG Cable with MC4 connectors.  It can carry at least 30 Amps and 600 volts. 

Strand Design No./Dia. (48/0.295mm)  Conductor Resistance 20°C/KM (≤5.94Ω)  600V Outer Diameter (6.2mm)  Rated Current at 20°C (57A) 

Conductor (Stranded Tin Plated Copper)  Insulation/Sheeth (XLPE)  Rated Voltage (600V)  Temperature Range (-40°C~90°C) 

Halogen Free  (Yes)  UV Resistance (Yes)  Mini Bending Radius (6x Outer Diameter)