METRIC, 3/8” DRIVE, FLARE NUT, STANDARD LENGTH, CHROME HAND SOCKET SET. Flare nut sockets are specifically designed for Lambda probes, featuring an open section that facilitates easy use with wires and connectors. Input Drive Size: 3/8" Drive Shape: Square Type: Flare Nut Socket Set on Rail (150mm) Output Shape: Flare Sizes Included: 8, 10, 12, 14, 17, 19