Gray/Silver coated shooter/plunger inner spring used on some DE/Sega/Stern machines.

Can also be used on Williams/Bally machines.

DE/Sega/Stern #266-5001-04 (replaces 266-5001-02).

Spring tension from lowest to highest:
Blue (266-5001-05)
Green (266-5001-04)
Standard (10-148-1)
Orange (266-5001-07)
Purple (266-5001)
Gray/Silver (266-5001-14)
Red (10-148-2)