BESTFIT Clock Mainspring for Travel Alarm Clocks 4.30mm x .25mm - No. T430-5

Bestfit System #77 Clock Mainspring for travel & alarm clocks, Dennison 34 x 0 x 29½, presumably a TIME side spring, Regular tongue end, No. T430-5, 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