master cylinder fittings

looking for a bit help regards m/c
doing the servo/mc brake upgrade to my 89 cab clipper(not gti)as the faq guide on here.
just wondering there are the two fittings attached to m/c bottom 2 outlets(rearbrakes i think) about 1.5 inch long.brake lines attach to these.
what are they and will they need to be used in the upgrade.
the new 22mm unit is only the 2 outlet one.
they are not brake light switches.
any help appreciated
bobby