This is a standard IEC320 C13 to C14 connector cable. If your TDP lamp does not have a long enough cord to reach the socket in the D-11B and D-11B1 replacement TDP heads, an extension cord like this is necessary to make the connection.
Simply plug the C14 Male end into the lamp cable and then connect the C13 female end to the socket on the lamp head. Its 12-inch total length is long enough to make the connection without the extra length to cause a mess.
Length: 12 inches
Type: IEC320 C13 to IEC320 C14