This is a NOS Elgin 12s roller table with jewel that is in very good unused condition.
NOS 3.7mm Diameter Roller Table-Elgin 18s? Parts Spares Repairs
This is a listing for a roller table that was in a bottle of Elgin 18s balance staffs, so I would guess this is Elgin 18s as well. This measures 3.7mm in diameter and doesn’t have the jewel. This is in very good unused condition. Please see my other listings for similar items.