Upper panel: optical spectra of WISE J231101.29+020505.3, counterpart associated with the BZB 2FGL J2310.9+0204 classified by Ackermann et al. (2011a). Our observation clearly shows a featureless continuum, which confirms its classification, in agreement with the recent observations of Shaw et al. (2013a). The average S/N is also indicated. Middle panel: normalized spectrum. Lower panel: 5′ × 5′ finding chart from the Digital Sky Survey (red filter). The potential counterpart of 2FGL J2310.9+0204 is indicated by the red circle.