The X-ray telescope XTEL is based on the coded aperture mask principle, as in JEM-X telescope on INTEGRAL [81]. A 10 x 10 cm microstrip proportional counter (MSPC), similar to LEPC on SODART, will be used in the focal plane, as it provides a good spatial resolution and high quantum efficiency in the 0.5-10 keV energy range [82]. A 25 x 25 cm coded mask in combination with the MSPC detector will suffice for the study of GRBs and X-ray transients. For a distance between the detector and the coded mask of 850 mm, the fully coded field of view becomes 10 degrees and assuming a pixel size of 2.5 mm, the intrinsic angular resolution becomes 10'. This value that can be further refined to about 2' by centroid fitting of a better direction. The efficiency is larger than 70 % between 1 and 8 keV, with an energy resolution of 0.3 x square root (E/1 keV).