QUaD, an acronym for QUEST at DASI, is a ground based cosmic microwave backrground (CMB) polarization experiment located at the South Pole. QUEST (Q and U Extragalactic Sub-mm Telescope) was the original name attributed to the bolometer detector instrument, while DASI is a famous CMB interferometry experiment credited with the first detection of CMB polarization. QUaD uses the existing DASI mechanical infrastructure but replaces the DASI interferometric array with a bolometer detector at the end of a cassegrain optical system.