This ONYX toner can be used for compatible models such as Formax ColorMax T4i  & ColorMaxT6i. These models use a dry toner-based printing process, so it is ideal for printing envelopes that will be subjected to harsh weather conditions. These long-lasting toner cartridges will print up to 38,000 pages before needing replacement, allowing you to complete projects without wasting time replacing toner. The T6i is capable of printing in extremely fine detail.