1. What's in your
picture is NOT the Spark-Plug,
it's the
Oxygen-Sensor (
36533-KYJ-900).
It is recommended to replace the sealing WASHER
(90454-MC7-000) and then put the O-SENSOR back in place. As with the plug, it must not be tightened beyond what is allowed.
____
2. The type plug belong to Honda CBR250R (2011) is:
SPARK PLUG (SIMR8A9) (NGK)
31916-MEH-003
3. Yes, that plug is IRIDIUM Type.
4. IU24 This is the code of the equivalent NGK plug, Honda Part No 31916-MEH-003, that manufactured by
DENSO