Aerialtronics makes the Altura Zenith ATX4 and ATX8, but no 'Altura Zenith 16' / ATX16 variant could be verified as a real product (the '16' likely stems from the ATX8's 'up to 16 kg of vertical thrust' spec).
Country
Netherlands
Review-stage catalogue data — specs corroborated from manufacturer and secondary sources; not for procurement decisions.