  Delta Scuti ($\delta$ Sct) stars are intermediate-mass pulsators, whose
intrinsic oscillations have been studied for decades. However, modelling their
pulsations remains a real theoretical challenge, thereby even hampering the
precise determination of global stellar parameters. In this work, we used space
photometry observations of eclipsing binaries with a $\delta$ Sct component to
obtain reliable physical parameters and oscillation frequencies. Using that
information, we derived an observational scaling relation between the stellar
mean density and a frequency pattern in the oscillation spectrum. This pattern
is analogous to the solar-like large separation but in the low order regime. We
also show that this relation is independent of the rotation rate. These
findings open the possibility of accurately characterizing this type of
pulsator and validate the frequency pattern as a new observable for $\delta$
Sct stars.
