The N21D is specified as the stylus replacement for the Shure M7-21D cartridge. The Vivid Line LP Tunes stylus for the Shure M7/N21D phono cartridge features a highly polished Vivid Line diamond that performs significantly better than the underachieving conical tip that was fitted in the original Shure cartridge. You will hear noticeably better sound quality, clarity, and detail above and beyond what you were used to hearing with prrevious. Welcome to the Vivid Sound Quality!