These ones are ccmt carbide inserts.
They came as a set of 7 I think, including a boring bar.
The only problem I have with them is they only have 2 positions before you have to toss 'em.
A triangular insert has 3 new positions and they cost about the same amount.
The thread cutting inserts only fit in triangular holders as well.
Great tools, cut well, but hey do have their issues.
My set was ~$235 Canadian and there are 3 of them that I have yet to use.
If you are going to do a lot of aluminum, just get high speed steel and grind your own tooling. You can find patterns for almost any shape online and HSS does a nicer job because you can get them a lot sharper than carbides.
I like a belt sander to do most of the rough work and then I'm using a 3M wheel to take the burr off and polish the tool a bit. 2 or 3 strokes on 1500 grit wet dry (glued to a piece of plywood) and the tooling is literally razor sharp. I test them on my arm hair ^_^
I have run a lathe with an 18 foot 6" bed and a three foot sweep (used for turning logs for log homes)
The rough cutters were carbide to take the most material and the finishing cutters were always high speed steel because the sharp edge kept the finish quality high.
Carbide is a PITA to sharpen compared to HSS too