These are a quick alternative to the older screw block terminals. As a way of permanently or temporarily joining 2 cables they are ideal. It has a easy lever lock and are at a low price. They are easy to use, just pull the lever up, insert a conductor and push the lever back down. They are 13.2mm x 8.4mm x 18.8mm (W x H x D). Use on conductors from 0.14 to 4mm2