Unfortunately, our supplier does not yet have this product in their catalogue. We cannot add it at the moment. Perhaps it will be possible in the future.
As Pattyfit said, it should be. Bear in mind that this kit isn't compatible with NVME SSDs (the fastest, in other words) but it does the job largely anyway as a second hard drive, you'll still get 500MBps. Otherwise, it's USB-C, so it's all good.
So, I bought the above model to go with my MacMini 2021 model. The thing can take an SSD. And it's actually clear in the product description:
"Compatible with 2020 M1 Mac Mini & 2018 Mac Mini. Not available in space grey. Does not support 2017 & earlier Mac Mini models."