The Epaulet Skimmer (Orthetrum chrysostigma) males, like most Skimmers, are blue frosted. 
They are recognizable by their size: they are clearly larger than species such as the Small Skimmer (Orthetrum taeniolatum) and Southern Skimmer (Orthetrum brunneum). 
Viewed from above, the best identifying feature is the constriction of the upper body and, in fresh males, the markings on the thorax. 
Females are sandy colored with the same clear markings on the thorax.
The Epaulet Skimmer is found in North Africa, southern Spain, the southern coast of Turkey and some Greek islands such as Lesbos.

1st & 2nd photo: Jaraicejo area, Cáceres, Extremadura, Spain, 8 June 2024
3rd & 4th photo: Monfragüe National Park, Extremadura, Spain, 11 June 2024
5th photo: Monfragüe National Park, Extremadura, Spain, 12 June 2024