I don't know what you would call it. I have a set of Bully Dog Stage 1s in now but I have always heard that the DD 2s had a superior swirl character that other injectors do not have. It appears to be a significant investment over Bosch 275s. ( I have sold a number of new 275s for $269 for the set). I probably am a buyer for a nice clean set of DD 2s for around $250. My Bully Dog 1s really smoke if you get behind the turbo even with the EZ choked all the way back. In any event, I am my own warranty co. in another 15,000 miles... ... ... ... ... ... .....