My second hand Mana 850 bars (£56

) arrived yesterday and the 1200 sport risers are on their way
Looking at the bars I'm a bit puzzled.
I thought the Mana bars were "plug and play, but the ends are tapped with a large thread so I don't understand how the bar end weights should fit.
Somewhere in the recesses of my mind I recall something about spark plug thread can't remember the relevance and a search hasn't revealed anything ... yet
Can anyone advise please?