Cabochon Gem End

2mm: 2.6 diameter x 1.1mm thick, set with a 2mm stone.

2.5mm:3.3mm diameter x 1.25 thick, set with a 2.5mm stone.

3mm: 3.7mm diameter x 1.4mm thick, set with a 3mm stone.

Shown on a 16g threadless post.