Felsa 4000, 4002, 4004-4009, 4031, 4033, Gruen 550SS mainspring NOS Swiss alloy!
Specifications
| All Returns Accepted | ReturnsNotAccepted |
| Metal | Alloy |
| Country/Region Of Manufacture | Switzerland |
| Compatible Brand | FeLsa |
| Type | Mainspring |
| Compatible Model | 4004-4009 |
| Brand | Gruen |
Felsa 4000 mainspring. Fits all the 4000 based calibers. 4000, 4002, 4004-4009, 4031, 4033.Auto winding models. Also fits any brand that used the Felsa movements above.For example Gruen 550ss, 580cd, 580ss and Elgin 813, 854, 885. Also MST caliber 441. Generale Ressorts part #3700X or 3700-2X or Best fit #WA41. Please note that originally Felsa used a separate mainspring bridle so if you barrel has that inside you will want to remove that before installing this spring.Reason is this spring has the bridle spot welded to the end so there is no need for the old bridle. This is a new old stock alloy spring. Swiss made vintage mainspring.You can buy one, two or four piece lots.Choose the amount you want from the drop down list above.Ask questions before you buy.Thank you for looking!
