#2 Yellow Dry Method Non-Fluorescent ParticlesMagnaflux Non Fluorescent Magnetic Particles These yellow colored, non fluorescent magnetic particles are designed for effective dry method magnetic particle testing under visible light. They provide strong contrast on various metal surfaces, making them ideal for detecting surface and slightly subsurface discontinuities in ferrous metals. Whether used with a powder blower or shaken from a bottle, these particles can be applied during magnetization