Twenty Clock Keys Four 5 Pronged Winding Clocks Tools 2 Five Sided Clock Keys. This is a new set of two 5 sided clock keys. The sizes are: Size 2, 2.75 mm. Size 3, 3.00 mm. Size 4, 3.25 mm. Size 5, 3.50 mm. Size 6, 3.75 mm. Size 7, 4.00 mm. Size 8, 4.25 mm. Size 9, 4.50 mm. Size 10, 4.75 mm. Size 11, 5.00 mm 2 Five Sided Watch Keys. This is a new set of two 5 sided watch keys. The sizes are: Size 2, 1.75 mm. Size 3, 1.65 mm. Size 4, 1.60 mm. Size 5, 1.50 mm. Size 6, 1.40 mm. Size 7, 1.30 mm. Size 8, 1.20 mm. Size 9, 1.15 mm. Size 10, 1.05 mm. Size 11, 1.00 mm.