BESTFIT Mainspring 511P for Benrus AR, AT, AY, BD, ETA 765, 766, etc - Alloy

BESTFIT Mainspring 511P for Benrus AR-AT AY & BD, Wittnauer 7TN, Bulova 4AE, 4AH, ETA 765, 766, Font 28, 71, 175, 186, 191, 196, 204, 215, 221, 232, 218, 711 caliber movements, plus perhaps similar ébauche watches, white alloy, new in dirty envelope. See images for precise mainspring specifications. I likely have several of these so the one you get may differ slightly from the images. 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 suitable job of representing the item.