MTA (Mass Termination Assembly) connectors from Tyco Electronics, work by squeezing individual wires into slots in the back of the contacts. This is done with a special tool. The slightly narrower slot slices through the insulation and squeezes tightly into the wire. Creating a gas-tight connection between freshly-scraped metal surfaces. It is a reliable and quick way of connecting as long as wire of the correct guage. Pulling these connectors off the PCB by the wires can rip the wires out of the back of these plugs.The header can be fitted with an optional dust cover. This fits over the top of the housing keeping it tidy and preventing the wires from being pulled out.