A 316L Surgical Steel Threaded Ball. Available with either a 1mm, 1.2mm or 1.6mm thread and available in sizes of 3mm - 6mm diameter balls.
The 1.0mm wire threaded ball is available in 3mm.
The 1.2mm wire threaded ball is available in 3mm, 4mm and 5mm.
The 1.6mm wire threaded ball is available in 3mm, 4mm, 5mm and 6mm.
Packed in 10's per size.