Unique Markerplugs are The Answer to Every Engineer's Prayer!Markerplugs make available a way of gaining temporary access to a wide variety of connectors in a SAFE, FAST and EASY manner. Each Markerplug has either two or three color coded, spring loaded, quick connect terminals on one end. By pushing the end of the terminal, a slot is opened to receive and hold securely a bare wire test probe. The other end of the Markerplug terminates in one of a variety of connectors. If you have ever been in a situation where quick or convenient access is needed to this wide variety of connectors, you will appreciate just how useful Markerplugs can be.