Almost all vehicles use pneumatic struts to hold up the hood. They’re filled with inert gas that hold structures open. The lift supports store the energy when closed, and when they open, the energy is released. Aftermarket hoods made of carbon fiber or fiberglass have a much lower flex tolerance in their internal structure compared to a metal OEM hood. This is why aftermarket hoods are more lightweight. These hood struts are specifically made to support a lower weight so that you aren't putting undue stress on your new hood by using OEM pneumatic struts. The OEM ones are made for a hood that weights more than twice as much, so it goes to reason that a more lightweight hood will require struts that support less weight.