Poly Voyager Free 20 Black Earbuds +Basic Charge Case
Lithium-ion - Up to 12 hours (listen time, ANC off); Up to 8 hours (listen time, ANC on); Up to 42 hours (earbuds and charging case, ANC off); Up to 28 hours (earbuds and charging case, ANC on); Up to 4 days (standby time)