In male Red-faced Skimmers (Orthetrum chrysis), the total body length ranges from 41 to 48 mm.
The male has a red face and dark grey eyes.
The thorax is dark brown and the abdomen is red.
The female Red-faced Skimmer is reddish brown.
This species is easily confused with the Orange Skimmer (Orthetrum testaceum) but the thorax of Orthetrum testaceum is reddish (Orthetrum chrysis has a brown thorax).
Also, with Orthetrum testaceum, the brown colour at the base of the wings is more prominent.

1st & 2nd photo: Koh Chang, Thailand, 5 January 2010
3rd photo: Tub Kaek Beach area, Krabi, Thailand, 2 February 2013