You need to know what watts the headlights are, to make sure the cable can take the load. This is critical for the power cable as it supplies all the power needed.
55 w low beams will pull 9 amps, 60w high beams a tad more (divide watts by volts; 55/12= 4.5 (or actually 110/12 = 9.16))
So on high beam you are going to need a cable to can cope with 20 amps (working on all 4 lights being on).
That harness looks at a glance to be 3mm wire which tops out at 20amps - in a quality cable. "Yes" it will work but with barely enough redundancy to cover you driving down a dark country road at night.
I went 5mm power wire for my setup and 3mm wire for the light harness. Overbuilt it, won't worry about it again.
If you want to buy something, look at these guys:
https://bluewireautomotive.com/products/headlight-relay-booster-power-wiring-harness-kit-40amp-h4