They also have the ".com" variant.It's one of those but the website on the cart is with .com. The ones nds cart sells are .com.cn
While the .com.cn is a better card, it is a different card and one that is not (as of now) compatible with ntrboot.
AFAIK r4isdhc.com cards are DSTT clones and r4isdhc.com.cn cards are Ace3DS clones.