Ronda Mainspring No. 387 for ETA caliber 1045 & Eterna caliber 1050 - Alloy

Ronda No. 387 Ronda-Flex Alloy mainspring for 5¾ ligne ETA caliber 1045 & Eterna caliber 1050 movements and perhaps others, new in open envelope. See images for precise mainspring specifications. I specialize in hard to find watch parts so I usually have whatever you might need and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item.