This directory contains precompiled library binaries that the SeqAn library depends on (called contribs). They come in two variants, 64 bit (ending in -x64.zip) and 32 bit (ending in -x86.zip). Details can be found in the How To: Install Contribs on Windows.
Download the most recent versions
You can install both variants in parallel.
The files are named seqan-contrib-D${TIMESTAMP}-${ARCH}.zip where ${TIMESTAMP} gives the build date and ${ARCH} gives the architecture (x64 for 64 bit, x86 for 32 bit Windows).