The tape within this genuine Brother MK621BZ cartridge is Black on Yellow in colour, making it easily readable in most circumstances. All 8m of the original Brother M-K621BZ tape measures 9mm in width, making it a perfect fit for the majority of items around our house or workplace. This Brother M-K621BZ tape cassette is an ideal organisational tool, and we are sure that you will be pleased with the look and durability of the labels it produces. The adhesive used on the tape within the Brother MK621BZ is incredibly strong, helping labels stick to most common surfaces with ease.