Acekard has been out of production for a while, and there is no stock at R4-DS-AU. Please pay attention to the clone AK cards on the market.
For Original Acekard 2 or Acekard 2i, you can download AKAIO kernel 1.9.0 from akaio.net.
If you want a replacement, recommend DSTWO card compatible with your 3DS XL, 3DS, 2DS, DSi XL, DSi or DS Lite.