(Sorry if this is the wrong section, I'm not sure what the GBA SP is considered around here)

So I was reading up on the available grips for the GBA SP and I found this.

Keep in mind that I was mainly looking for grips since I find the SP so uncomfortable, but a grip with benefits would be interesting too. So can anyone tell me about this thing, and if there's anything I should be warned of before buying it?

Thanks in advance.