Upper Thread Tension Check Spring - Singer Part # 43946
-New thread tension check spring
-Part # 43946
-Fits Singer models 31-15, 31-17, 31-18, 31-19, 31-20, 31-29, 331K, 44 Class
-New thread tension check spring
-Part # 43946
-Fits Singer models 31-15, 31-17, 31-18, 31-19, 31-20, 31-29, 331K, 44 Class