Spectral energy distribution of HESS J1943+213. Empty blue circles are the WISE data and the red circles the CAHA results. The red butterfly is the Fermi-LAT best-fit power law and the 68% error contour. A 2σ upper limit is reported for the LAT data points if TS < 9. Other data were extracted from Abramowski et al. (2011): the black point is the NVSS measurement, the yellow, blue, and red butterflies are respectively the Chandra, Swift-XRT, and INTEGRAL-IBIS measurements. The green point is from the 70-month Swift-BAT catalogue (Baumgartner et al. 2013). The upper limit is from INTEGRAL-SPI. The purple points are the Suzaku measurements extracted from Tanaka et al. (2014). The red line is the result of the SSC calculation for z = 0.2, and the grey lines were obtained for z = 0.03 and z = 0.45.