Wired headset with microphone - 3 or 4 conductor jack?

[TRS-80]

I just wanted to add, I purchased a cheap Road King model 910 recently (which is also a wired headset), I give a little mini review here.  But what I did not mention there is that it did come with a couple more plug adapters, for apparently different configurations, which I thought was pretty cool.  It worked out of the box though on PinePhone with whatever the default is without needing to use any of them.

By now I'm sure you have this sorted, just continuing to share what little info I have for others in future.  As this forum has been so helpful to me in finding little bits of info like this.