I was lucky enough to find the square-shaped Build Hands I wanted when building my ZZ.

They were brand new and cost 528 yen.

I'm using the L size for my ZZ.

These were called Dimensional Build Knuckles in the Build Fighters HGBC series, but they were renamed Build Hands in the option parts set.

I think the name comes from the "Dimensional" Haoh Style in Build Fighters Try, but perhaps they removed it because it's an option parts set separate from Build Fighters.

I was lucky enough to come across Build Hands | 邑楽(おうら)'s Gunpla works