Its a PVC minx (possibly a clone of the Edison minx). It is very stiff at first, but if you loosen the screws and lube it, it will be much better. Also, you will have to change the screws and springs eventually because the screws of the minx are very small and will loosen by themselves. Changing the hardware will make it cut corners better, pop less, and turn faster.The stickers are crap, so buy Cubesmith stickers, too. The minx also has a crispy feel when turning.
I had 3 of these and I recommend it.