Oppo unveiled the A77 5G in June and followed up with a new 4G version in August. These are expected to be joined by the A77s soon, which has appeared in a leaked poster revealing its design and specs. The Oppo A77s is a version of the A77 4G with a different chip (Snapdragon 680) and more RAM (up to 8GB). The A77s will come in Sky Blue and Starry Black colors, but it's unclear if there will be a Sunset Orange version with the Fiberglass-Leather Design. There's no word from Oppo about the A77s yet, but the smartphone was certified by Thailand, India, and European Union's authorities...
Source: https://www.gsmarena.com/oppo_a77s_full_specs_design_leaked_poster-news-55950.php