connector
Board-to-board connectors often have 2 fitting nails (name depends on vendor), e.g. Molex 505066-0622:
The product specification includes many properties of those fitting nails, e.g. contact resistance:
Does this mean that fitting nails can be used as regular pins? So a 6 pin connector such as Molex 505066-0622 has in fact 8 pins? Also as the contact resistance of the fitting nails is lower, they are even better suited for transmitting power?
Those are "wire-to-board" connector assemblies. You need to look for hints on its brand as the one you have there is a matched mated system. An important specification to aid identification is the pitch or distance between the center-lines of two pins: usually either 0.1in (2.54mm) or 0.156in (3.96mm).
Although the picture is a bit unclear, I think what you have there is a TE 0.1in connector from their CST-100 system. Try this page and check if the product photo and the 3D PDF matches your connector.
When faced with an unknown connector, try exploring catalogs like the one from RS or TE's picture search.
They look like they are adapters for shrouded banana plugs. As far as I can tell from your photograph, the red plugs have bodies which narrow after a ridge and the black ones have a uniformly narrower diameter. The narrow bodies fit inside the shrouds of the shrouded plugs.
Best Answer
Molex Glossary Terms state:
From Molex 505066 Product Specification:
The primary purpose of fitting nails is to keep connector on SMD PCB, but are speced for 50V AC or DC at 3A. Therefore they can be used for power.