Complex sentence: The AK-107 is a Russian 5.45 mm assault rifle developed from the AK-100-series and features a "balanced" operating system, similar to that used in the AEK-971.
Split into simpler sentences: The AK-107 is a Russian 5.45 mm assault rifle developed from the AK-100-series. It features a "balanced" operating system, similar to that used in the AEK-971.