Left: Predicted companion fraction of massive (M > 8 M_⊙) main-sequence SMC stars in post-mass transfer binaries as function of their mass, including system in which the companion (in general a NS) was unbound during the SN, and excluding merger products. Models that we assumed to appear as emission-line stars are marked with black or white dots (depending on the background colour). Above each mass bin we give the total number of system in that bin. The total number of each companion type is given in the legend distinguishing between emission-line star (first number) and normal OB star (second number). Right: Absolute number of compact companions of OB stars (outer pie chart), and the assumed SN type of the NS progenitor (inner pie chart), predicted by our fiducial SMC population.