Swartchild Black Shield TIME Mainspring for Westclox Travette Alarm Clock

Swartchild Black Shield TIME Mainspring for Westclox Travette Alarm Clocks from the 1930's and 1940's (and perhaps beyond). Could also very well fit in other alarm and travel clocks as well. See images for precise mainspring specifications. I specialize is hard to find watch parts and all watch parts are unconditionally guaranteed. Images do a suitable job of representing the item.