Mine was purchased a few days ago at HKD128 (discounted) at IKEA.
It's definitely not aluminum as magnets are attracted to it very strongly. It feels like steel but not sure if it's carbon steel.
It rusts very very quickly so dry it immediately after use. (mine, at 2nd use meaning, not too well seasoned yet, rusted right after an hour - I used it for steaming food... I took the food without clearing the water or drying it... came back after eating the food and it rusted.
I cleaned it, and seasoned it a few times with rice barn oil: rub with oil, heat until smoking... rub again... heat again... cool down, rub again, heat again...
Hopefully it becomes better and better as my Lodge cast iron skillets.