Wire nuts (sometimes called Marrettes or Wire connectors) are UL listed fasteners used to make a tight connection between two or more electrical wires in an electrical box. Made of flame-retardant materials, wire connectors prevent wires from contacting exposed metal surfaces, which could cause a dangerous fault or short circuit.
ecobee Switch+ comes with 4 wire connectors in the box. To use them hold the wires you’re connecting parallel to one another so that the ends are aligned. Holding the wires together and parallel, insert them into a wire nut. Twist the wire nut clockwise until secure. Double-check by tugging on the wires gently. If they separate or shift inside the nut, realign the wires and replace the wire nut. Twist the wire nut clockwise until the wires are secure.