These high-quality terminal blocks / screw terminals are typically used to connect loose wire to circuit boards. Simply turn the screw to open the jaw, insert the wire, and tighten the screw to close the jaw and clamp the wire in place.

These specific terminals work with wires ranging from 30 – 16AWG and have alignment pins on each end that allow them to lock together to form larger configurations. The pitch measures 5.00mm, however it is close enough that in smaller lengths these can be used in most breadboard pitch perfboards as they will hit every second pin. It should be noted that these pins are thicker and may need to be shaved down to fit in some perfboards.