mediumLarge

PhoneFontSizeMediumLarge, 25.333 px.

The slot the ramp had but the theme did not, which is why four controls that Microsoft sized up from the page default were all set in normal: a text box, a list picker and an autocomplete box are PhoneFontSizeMediumLarge in the toolkit's Generic.xaml, and a control with nowhere to point at ends up pointing at the default.