You Do Need power plug adapter while traveling from Balearic Islands to Czech Republic.

Here is Why You Need An Adapter

The outlet and plug type used in Czech Republic are C and E and in Balearic Islands are C and F. This is how they look like.

Balearic Islands

In Balearic Islands, outlets of type C and F are in use.

Type C

Type F

Czech Republic

In Czech Republic, outlets of type C and E are in use.

Type C

Type E