SKROSS1500220 Country Travel Adapter - World to UK - White

I bought this for the iron we had brought back from living in Italy but the 2 prongs don't go in??

There appears to be red plastic in the holes on my adapter and my 2 prong plug won't go in...do I need to take it out??

Is it available for South Korea plugs?

There appears to be red plastic in the holes on my adapter and my 2 prong plug won't go in??