Jaws lock in an open position to be able to get over a line and onto a flare nut.
Push the wrench against the fastener to close the jaws automatically. The jaws will bite on all 6 flats of the hex unlike traditional flare nut wrenches.
Spring loaded design allows the wrench to ratchet.
Designed to overlap at the opening so that no torque is applied to the pin/spring when in use.
Spring loaded design allows the wrench to open enough to be used for the SAE equivalent sizes.