Transfer belt installation is recommended every 100, 000 images. The Lexmark Optra C710 Transfer Kit contains a replacement transfer belt & transfer roller that work together to ensure vibrant color printing for up to 100, 000* images. For use with the Lexmark Optra C710, C710n & C710dn color printers & the Optra Image C710sx. Yield: * Up to 100K images. One 4-color page = 4 images.