17 New Bergeon Unbreakable Mainspring Winders. This is a new set of clock mainspring winders. This set of winders are for Nivaflex mainsprings. These winders come in a handy wooden storage box. These are made in Switzerland. The box measures approximately 6 1/16" x 4" x 2 1/8" (154 x 102 x 54 mm). There are 17 sizes included. The sizes are: Size 00, 2 mm. Size 0, 2.25 mm. Size 1, 2.5 mm. Size 2, 2.75 mm. Size 3, 3 mm. Size 4, 3.25 mm. Size 5, 3.5 mm. Size 6, 3.75 mm. Size 7, 4 mm. Size 8, 4.25 mm. Size 9, 4.5 mm. Size 10, 4.75 mm. Size 11, 5 mm. Size 12, 5.25 mm. Size 13, 5.5 mm. Size 14, 5.75 mm. Size 15, 6 mm.