These plasmids are used for bacterial genome engineering. For more information and a protocol look here: http://openwetware.org/wiki/NanoBio:_Protocol_for_gene_knockout
pKD46 is temperature sensitive so culture at 30C if not using for recombination.
pKD3 and pKD4 can only be replicated in a lambda pir strain.
pCP20 is temperature sensitive so culture at 30C. Contains FLP recombinase for removing the antibiotic resistance marker in your cells.
These plasmids come in the bacterial strains originally provided by the Yale CGSC (see links above).