BESTFIT Clock Mainspring for Travel Alarm Clocks 2.60mm x .16mm - No. T260-3

Bestfit System #77 Clock Mainspring for travel & alarm clocks, Dennison 17 x 6½ x 19½, presumably a TIME side spring, Regular tongue end, No. T260-3, steel, new in envelope.  See images for precise mainspring specifications. I specialize in hard to find watch & clock parts and all parts are unconditionally guaranteed. Images do a pretty good job of representing the item