they're a carbon lining inside an aluminum shaft. For target shooters who want a lot of weight, they might be good...but I can't think of why target shooters would shoot lots of weight in arrows.
For hunting...why pay all that money for an arrow you are likely to use ONCE on an animal and then throw away...or stake a tomato to after you do? I don't get the usefulness of them -expensive, easy to bend, and the lining probably flakes off inside the shaft when it bends and unlike the ones that were carbon on the outside you CAN'T see carbon flake off on the inside...so I advise don't waste your money.