MIKUNI MAIN JET, SMALL ROUND 127.5
MIKUNI N102.221 series Main Jets (& 2 Stroke Power Jets)
Commonly known as:
“Small, round, slotted Mikuni main jet/power jet”
Looks a lot like a Keihin 393 series jet, but the thread pitch is slightly different
Used in original equipment CV carbs on some Kawasaki, some Yamaha, Mikuni equipped Triumph