2x rs232 https://allegro.pl/listing?string=Karta%20PCI%202x%20RS232
4x rs232 https://allegro.pl/oferta/axago-pcea-s4n-kontroler-pci-express-4x-rs232-11722437156
4x rs232 https://allegrolokalnie.pl/oferta/kontroler-pci-4-x-rs232
4x rs232 https://allegro.pl/oferta/axago-pcea-s4n-kontroler-pci-express-4x-rs232-11722437156
4x rs232 https://allegrolokalnie.pl/oferta/kontroler-pci-4-x-rs232
You can't have too many antennas...
