Even the best diamond needles wear out after some time - conical needles after about 500 hours, elliptical needles after 300 hours, microlinear needles after 1000 hours and Shibata needles after about 800 hours. That's why Audio-Technica has designed its VM95 Series Dual-Moving Magnetic Cartridges to be interchangeable between pickup needles, allowing the cartridge itself to be used almost indefinitely. So when the stylus wears out, you don't have to buy a new cartridge, just a replacement stylus - or upgrade your system with a different, higher-quality stylus.