  LOFT (Large Observatory for X-ray Timing) is an X-ray timing observatory
that, with four other candidates, was considered by ESA as an M3 mission (with
launch in 2022-2024) and has been studied during an extensive assessment phase.
Its pointed instrument is the Large Area Detector (LAD), a 10 m 2 -class
instrument operating in the 2-30 keV range, which is designed to perform X-ray
timing of compact objects with unprecedented resolution down to millisecond
time scales. Although LOFT was not downselected for launch, during the
assessment most of the trade-offs have been closed, leading to a robust and
well documented design that will be reproposed in future ESA calls. The
building block of the LAD instrument is the Module, and in this paper we
summarize the rationale for the module concept, the characteristics of the
module and the trade-offs/optimisations which have led to the current design.
