A connector assembly including a connector body with a spring clip including a first free end for engaging a side wall of an electrical box upon installation. During insertion of the connector body the first free end engages the knock-out hole perimeter and deforms so as to permit further insertion. Once the connector body is fully inserted, the spring clip cooperates with a lug on the connector body to hold the connector assembly onto the electrical box. The connector body includes one or more spiral indentations for engaging a convolution of a metal cable. The spring clip biases the cable toward engagement with the spiral indentation to yield improved performance characteristics.