Black Flute
From PokéHeroes Wiki
A Black Flute doubles your breeding chances at the Daycare for 30 days.
How to obtain them
They can be found and bought at the Item Shop for 300 Nuggets 
for Normal Users and 270 Nuggets for Premium Users. Alternatively, you can also buy a Black Flute for either 400 Nuggets for Normal Users or 360 Nuggets for Premium Users, respectively, where it's included in a Combo Pack with a Blue Flute.
They are also sometimes bundled with limited Premium sale offers.
How to use it
It can be blown and activated from the Daycare page.
Other
- Blue Flutes are not tradeable.
