New Replacement Upper Tension Spring 

Part # 4124555-01

Fits Viking models: 1140, S205, 210, 230, 250, 310, 315, 320, 325, 330, 335, 350, 415, 425, 500, 530, 535, 540, 545, 550, 555, 600, S605

Scandinavia Series: 100, 200, 300, 400

Platinum Series: 715, 730, 735, 750, 755, 770, 775, 950E, 955E, Plus

Sapphire Series: Oscar