The Sony 24-70mm GM Lens is one of the first in Sony’s G Master series of high-end lenses for the e-mount. They’re designed to be used with the a7 series of full frame cameras and promised the high resolving power needed for high-resolution sensors.
The company says the GM series has also been designed with Bokeh; that’s the quality of out-of-focus rendering as one of the key design considerations. They’re also designed to be both dust and moisture resistant.