These are like the fancy electronics equivalent of the wire nuts electricians use to bind wires together. They are a lot easier to use as well! Each block connector has a metal block inside and three levers that snap open and close to bind stranded/solid-core wire. No screwdrivers required! They're super handy for free wiring and can handle up to 20A at 300V with UL listing so you can also use them for mains wiring. Use any wires from 12 AWG down to 28 AWG. Each pack contains one 2-wire Block connector.