The notorious Colombian kingpin's bro, Roberto, is adding to his tech portfolio by unveiling one of the world's first foldable smartphones. Based on the ad ... sexy women in lingerie will especially enjoy using it.

According to his company, Escobar Inc., the flexible screen Android easily folds out into a 7.8-inch screen tablet ... and comes with all the top-of-the-line bells and whistles.

Its name -- the Escobar Fold 1. Retail price -- $349. The company says they'll sell out quickly, because it's only producing 100,000 units to start ... so get 'em while they're hot.

Of course, the pioneering new phone comes a few months after Roberto got into a business beef with tech guru Elon Musk ... over their competing flamethrowers.

We broke the story ... Pablo's bro threatened to take legal action against Musk, claiming Elon jacked his idea after one of his engineers paid a visit to the family compound in mid-2017.

However, days later Roberto changed his tune and offered a solution to Musk -- get Trump to issue him a pardon so they can partner up ... and get into the weed biz.