By using these MC4 combiners here, you can run 4 panels (or 4 strings of panels) in parallel.
You get a pair of connectors: One (1)Male to (4)Female and one (1)Female to (4)Male for running 4 strings of panels input to 4 strings of panels output.
Brand: Rock Solar
Anti-aging and resistance to ultraviolet radiation
Cable length for each side: 160mm
Trunk Cable specification: 6mm2 (AWG10)
Branch Cable specification: 4mm2 (AWG12)
Rated current: 50A
Rated voltage: 1000V DC
Test voltage: 6000V(50Hz,1 min)
Contact material: Copper,tin plated
Insulation material: PPO
Degree of protection: IP67
Satety class: II