- This is a new 5 sided even number brass clock key
- This is used to wind clock mainsprings
- The clock winding key made of Brass (Sizes # 3,5,7,9,11)
- This key square hole Sizes: 3mm 1/8 in (3), 3.5mm 9/64 in (5), 4mm 5/32 in (7), 4.5mm (9), and 5mm 13/64 in (11) for use with winding clocks.
- If you have any questions or concerns about this item before you decide to purchase, please contact me