Goldring D42 stylus is designed to fit the current Goldring 1042 phono cartridge or old model 1040, a direct replacement when your stylus is worn - saving the cost of buying a whole new cartridge. Goldring cartridges generally last many hours until the stylus needs replacing. An indication of wear is a "duller" sound. Simply remove your current stylus by carefully pulling it away from the cartridge and replace it with the replacement.