This replacement bobbin case tension spring (part # 45789) is designed for Singer Featherweight and Model 301 bobbin cases. This small but critical component maintains proper bobbin thread tension for consistent stitch quality. Replace worn or rusty tension springs to restore optimal bobbin case performance.

Specifications:

• Part Number: 45789
• Type: Replacement (aftermarket)
• Function: Maintains bobbin thread tension
• Works with bobbin cases 45750 and 45751

Machine Compatibility:

Singer 221 Featherweight: Fits all variations of the standard model

Singer 222 Featherweight: Fits the 222 Free-Arm "Free-Motion" models

Singer Model 301: Fits Model 301 and 301A