FENDER 3250R NPS BULLET END 10-46. The best of yesterday and today. We started with our pure nickel wound strings and added our newly improved patented Bullet end. Designed especially for your tremolo-equipped electric guitar, the Bullet end lends additional tuning stability to the warm full vintage sound of pure nick. Bullets-the String for Strat guitars. Fender Super Bullets Nickel-Plated Steel (NPS) strings combine the high output and dynamic sound of steel with the smooth feel of nickel; perfect for rock and other styles of music where the guitar needs to cut through. Fender's patented bullet-end creates a sonic coupling between the string and bridge block, for rock solid tuning stability and increased sustain.