Those are for inserting into terminal strips.
female version of these which let you connect one male to one female connection on a single wire
Doing a shitty job, once, sucks!One cruise ship vid I was watching said they had 4000 km of wiring in it. that's nearly coast-to-coast! That must translate into tens of thousands of connections! I've noticed that ship wiring (such as on BC Ferries) is of the highest order. Have to.