Mean WHT spectrum of KIC 10553698 after correcting for the orbital velocity. The S/N in this mean spectrum peaks at ~200, and many weak metal lines can be distinguished in addition to the strong Balmer lines and He i lines at 4472 and 4026 Å. The continuum of the normalised spectrum was sampled individually in 100 Å sections. Shifted up by 0.2 is the model fit computed with tlusty/XTgrid. Line identifications are given for lines stronger than 30 mÅ in the model. The final parameters for this model fit are given in Table 3.