120v and 240v questions

Ok so I have an autopilot 8-light controller that is wired 240v. This controller can be wired in either 120v or 240v. and it has female plugs for your lights that will accept either the 5-15p (standard 120v) male, or the 6-15p (standard 240v) male.

I puchased a spydrx+ from my local shop and they accidentally got the one with the 5-15p male but I wanted to run it 240v. He sold me an adapter sold by nanolux that turns a male 5-15p into a male 6-15p so that you can plug it into a 240v 6-15p outlet.

My question is, since the light controller accepts both plugs, do I really need this adapter? or can I just use the 5-15p male plug and plug it into the 240v wired controller?

It won't matter in this case. The 6-15 is to keep you from blowing up your 110V devices, but since your device doesn't care neither will the plug.

that's what I thought, but someone told me that the 5-15p plug can only handle 125v max and that the contacts are made from different material in a 6-15p

Nah, same stuff, different orientation. Now, there are 15 amp rated 5-15r, but that's not the issue here.