What injectors have I got?

[JimX]

I bought a set of 550cc side feed injectors, but I'm not sure what they are. The seller didn't know either but assured me they were 550cc. Can someone let me know what they are?

They've got purple/red tops and what looks like a tiny Nissan logo on them, so small that the word "Nissan" doesn't fit (ie, it's a circle with a square either side). The part numbers say OF555425 and A46-90. On the screen in the middle it says "MADE IN JAPAN" and "JECS".