Hello everyone! Sorry! I don`t know if is allowed

Hello everyone!

Sorry! I don`t know if is allowed to write in English here, but I`m on my first post and I don`t know this...
I watch this forum from the beginning (used Google Translate) and I see that allot of you build a rework station based on LDZ`s project.
I want to build myself a rework station and I want to use LDZ`s project myself.
Anyone can tell me why in the firmware archive is 2 files? Eg. IR_16_2_6_7_7.hex and IR_16_2_6_7_8.hex

Sorry again for write this in English, but I don`t know Russian!

Thank You!

Самодельная ИК паяльная станция (часть 5)