Hampden Factory Mainspring 16s No. #4697 - Steel

Hampden Factory Mainspring for 16s movements, Factory No. 4697, steel, new in a well handled envelope. See images for further details. The envelope originally said 3696 but this is a 4697 as someone before me has notated and I verified - it's a hook end and the measurements are pretty close to what it says although I'd say it's more like a 18 x 6½. I specialize is hard to find watch parts and all watch parts are guaranteed. Images do a pretty good job of representing the item.