Photo: Snapchat Snap continues to forge ahead with its line of techy camera glasses despite previous generations largely proving unprofitable and/or unpopular. But hey, fourth time’s the charm, right? On Thursday, Snap announced its newest Spectacles smart glasses with built-in AR displays, but don’t expect to get your hands on them anytime soon — they’re not for sale. More on that in a second. Snap CEO Evan Spiegel debuted the company’s first true augmented reality glasses on Thursday, which come with dual 3D waveguide displays capable of overlaying digital AR effects on the world around you. A demo posted to Twitter shows Spiegel playing fetch with a virtual dog and watching virtual butterflies flutter about, with one landing on his outstretched hand. You can snap videos of moments like this and send them to friends with the click of a button, he said.