A phono cartridge is a micro-mechanical device at the tip of the tonearm on a record player. This device converts vibrational energy from the grooves of the vinyl into electrical signals that eventually produce the sound you hear from your speakers. This process involves a needle, a coil of wire, and a magnet within the cartridge, among other components. Some cartridges are more precise than others, and they all can wear out over time. A key component of a hifi audio system is an updated cartridge on your turntable. This can also prevent damage and wear on your vinyls due to a worn out needle. A wide variety of moving magnet cartridges are available, usually equipped with elliptical needles, or as empty headshells with leads.