What does flame boost buff from Dragonblaze give?

[dklm]

The skill Dragonblaze (F) gives a buff called flame boost but in the description and also when I hover my mouse over the icon it doesn't say what the buff does.  Any idea?

[sephy Kun]

It does in the skill description 

 

"Increase bonus flame damage from equipment by 40% and then increases it by 100 for 15 seconds"