Another thought: "RU" might be a model number. For example, "Model RU" or "Russian edition." Maybe "ok" is part of the model designation. But without knowing what "ok" stands for, it's hard to say.
Another thought: "RU" might be a model number. For example, "Model RU" or "Russian edition." Maybe "ok" is part of the model designation. But without knowing what "ok" stands for, it's hard to say.