  We have discovered a partially eclipsing white dwarf, low-mass M dwarf binary
(3 hour 54.41 second orbital period), SDSS J143547.87+373338.5, from May 2007
observations at the WIYN telescope. Here we present blue band photometry of
three eclipses. Eclipse fitting gives main sequence solutions to the M dwarf
companion of $M_S=0.15-0.35 M_{\odot}$ and $R_S=0.17-0.32 R_{\odot}$. Analysis
of the SDSS spectrum constrains the M dwarf further to be of type M4-M6 with
$M_S=0.11-0.20 M_{\odot}$. Once full radial velocity curves are measured, high
precision determinations of the masses and radii of both components will be
easily obtained without any knowledge of stellar structure or evolution. ZZ
Ceti pulsations from the white dwarf were not found at our 4 mmag detection
limit.
