What ever happened to the f/injectors with nitrous port?

Anyone know what happened to these? About 5 years ago or so some manufacturer came out with injectors with a nitrous port already installed...saving the hassle of adding and drilling and whatever. You just had to plumb in the nitrous to each injector off a main distribution block (easier than it sounds). I believe the kits were model specific.

I am not thinking of adding to the stang, but just curious on general principle.

Tnx.