Coca-Cola further promotes the idea of sharing with a new simple design solution for a bottle cap that has been recently unveiled in Colombia. A new cap allows to open a Coke plastic bottle only with another bottle—the project was developed by Leo Burnett in Colombia to inspire communication between freshmen on the first day of college.

The new bottle boosted sales (two bottles had to be purchased at a time to open each other) and helped students make friends. The new caps had special elements that made them work as puzzle pieces—only when put together, the bottles could click and be opened with a twisting motion. That was what the Leo Burnett Colombia’s team planned: to get strangers click immediately.

The new project follows in the footsteps of another friendship-inspiring effort by Coke, the Sharing Can. A regular can could split into two tiny versions, coming as an illustration of how happiness can grow yet bigger by sharing.