BESTFIT Clock Mainspring suitable for Kienzle Midget H300-1

Bestfit System #77 Clock Mainspring suitable for Kienzle Midget clocks and perhaps others as well, HOLE end, No. H300-1, 1940's or newer, steel, new in envelope. See images for precise mainspring specifications. I specialize is hard to find watch & clock parts and all parts are unconditionally guaranteed. Images do a pretty good job of representing the item