you may be able to make one using the images from the site and manual:
http://retro-bit.com/
http://retro-bit.com/manual/SRA_Adapter_IM.pdf
http://retrobit.com/
http://retro-bit.com/manual/
back box text:
SUPER RETRO(R) ADVANCE ADAPTER
FOR POUR PARA
SNES(R)/RETRO-DUO(R)/RDP(R)/SR3
Play original GBA(R) game cartridges directly on your SNES(R) or third party
16-bit console! The Super Retro(R) Advance by Retro-bit(R) comes outfitted
with a GBA(R) link cable port (link cable sold separately) for connecting up
to 3 Gameboy(R) systems, allowing you to play 4-player games like Mario
Kart(R). The SRA is an addition you must have for your retro gaming needs!
[replace (R) with Registered Trademark symbol.]
English:
- Plugs directly into the original SNES(R) or third party consoles
- Compatible with GBA(R) game cartridges
- Works with original and third party 16-bit consoles
- GBA(R) link cable port (link cable sold separately)
- 4-way game capabilities
UPC:
8 49172 00206 7
MADE IN CHINA
DESIGNED IN THE U.S.A.
hope this helps.