The Starlight Xpress spectrograph is a compact reflective grating spectrograph. This small unit packs a high performance flat-field concave grating into a module of only 136 x 120 x 75mm and 1.2kg weight. It also includes a built-in Lodestar X2 guide camera and an argon-neon calibration lamp. The input and output are T2 thread and it is compatible with most T2 thread input imaging cameras. We recommend the SX-694 as a good match. The spectral length is 340 - 900nM over a distance of 31mm and the resolution factor is in excess of 2000.