Enhance the efficiency of your calculator with this pack of 7 genuine Monroe P51S black/red calculator ribbons. Designed to provide clear and crisp prints, these ribbons are compatible with various models listed in the product description. They come in a unit type of ft and offer a yield of 16ft, ensuring long-lasting use. The black color ensures a professional look while the red color provides a clear distinction for positive and negative numbers. Ideal for use in office equipment, these ribbons are a must-have for any business.