The Philips GP 401 is a cartridge designed for use with turntables, offering compatibility with a range of stylus options, making it a versatile choice for vinyl enthusiasts. The GP 401 is compatible with the GP-400 mk III, GP-406 mk III, and GP-412 mk III, allowing users to replace styluses easily. Replacement styluses include the 946/D70, featuring an elliptical diamond tip for 33/45 RPM records, and various aftermarket options known for quality sound reproduction. It is worth noting that the GP 401 mk II variant also supports multiple styli from the SUPER-M mk II series, enhancing its adaptability. The BLACK DIAMOND stylus for the GP 401, notably, utilizes a unique design featuring a diamond cut to improve audio resolution, particularly in higher frequencies. Tracking force typically ranges from approximately 1.65 to 2.15 grams. Overall, the Philips GP 401 is recognized for its performance in delivering dynamic sound quality, akin to more advanced systems.