looks like a common steel core graphite faced header gasket. they look just like the hooker gaskets that came with my headers, hooker sells them & includes them with their headers. house brands like summit have them too that look just like these. felpros are definitely blue that wont fade to grey like these.
https://www.summitracing.com/parts/s...YEAQYBCABEgJm7
if you have quality headers like dougs with nice flat flanges & clean flat head surfaces, you shouldnt need expensive specialty gaskets, the steel core graphite gaskets work great when installed right & retorque the bolts after a few heat cycles then check periodically. some swear by high temp RTV alone or added to gaskets. also a good locking type header bolt helps a lot, summit sells nice stainless header bolts for cheap with serrations under the head to help keep them tight.
i have the cheap priced hooker graphite gaskets on a 500+hp E-head motor that are leak free after 7-8 years and lots of drag strip use & hard street miles. i use the supplied hedman paper gaskets on another car for 13+ years with no leaks and have had other cheap header gaskets on another car for 10+ years that was a daily driver & saw close to 100k miles. never understood the need for remflex gaskets and all the problems some people seem to have with headers.