These dongles are intended to be purchased with, or by customers that already have, any of the SMEMA Adaptor Family products;
They feature SMEMA Female Sockets, so are intended to be used with existing extension cables and are slightly longer than the SMEMA Male Dongles alternative.
You can create your own cables by using the wiring diagram shown below. Your factory IT professional may have a crimp tool for the RJ12 connection.
SMEMA Male Dongles are also available which are intended for direct SMT equipment connections and are slightly shorter to keep the installation neater.