Twist-on wire connectors, also known as wire nuts, are small plastic devices used to join two or more electrical wires together. They feature a conical shape and an internal metal spring that grips the wires when twisted. This creates a secure electrical connection, ensuring safety and preventing short circuits. These connectors come in various sizes to accommodate different wire gauges and are commonly used in residential and commercial electrical installations. Proper use of twist-on wire connectors helps maintain a reliable electrical system, making them essential for both DIY projects and professional electricians.