Blaster O-Ring Head with Copper Wire O-rings?

[Blastah'- FiveOh]

Have I been out of the loop for so long that rubber O-rings for cylinder heads have been replaced by copper wire?

I want to try out a used aftermarket head (1 piece single unit) that's cut for O-rings around the domes but has copper wire in the grooves.

I got the copper out and its like a copper piston ring, it's not solid. Black RTV is used for sealing the water jacket, no gasket is required apparently.

So...

1) Is the copper wire there because it's better than rubber O-rings?

2) If so, is it re-useable, and if it's not where would one go to purchase new pieces.

3) Or should I find the rubber O's

Thanks...