This is the M80 Acoustic Dreadnought guitar gig bag.  Possibly the best acoustic gig bag out there!

Mono designed the M80 Series from the inside out to be the lightest, thinnest, strongest, most versatile carrying solutions for the professional musician. A hybrid case featuring an ultra light laminated foam shell with strategically placed ABS panels, providing an unmatched level of protection for your most prized investments. Smart features like the Clip/Tuck straps make for easy airport travel, while the streamlined profile helps you slip through the crowds.