i am cutting down a set of Maltby irons for my daughter. They have Mitsubishi kura kage graphite shafts. When I trimmed the butt end I found a two and one half inch white plastic insert in the shaft. They have a cap that keeps them from sliding down inside the shaft. I a curious about their purpose and do I need them before I regrip? These were assembled by Maltby .

Thanks

I suspect it’s the insert for a counter balance, see part number GW0113V.
I used these on some women’s test irons.
As far as needing them it depends on the player.