TOP > Various Settings of the Product > Product’s [Settings] Menu > [Information] Menu > [Counters] > [Head]
[Head 1] shows the current print distance. When you replace the print head and the counter is cleared, the value of [Head 2] appears in [Head 3] and the value of [Head 1] appears in [Head 2]. [Head 1] will start to count from 0 again.