According to the product page-
"You can plug it into your SNES to play GBA game. Use your SNES joypad instead GBA joypad. You need to plug AV cable to this adapter for video output. It can not use SNES AV output. It can use on both PAL and NTSC version SFC/SNES. But its AV output is NTSC. (Take care)"
As I have heard, those devices are systems-on-a-chip that use the host console only as a power and controller input device and nothing else of its hardware capability.