Question about Philips MAS LEDtube

I honestly can't understand how it can be energy efficiency class "A", I bought a philips led tube which is still in the Galaxus store: philips 12.5watt 2100 lumens and it's a class "C" but it's more efficient than this one based on watts/lumens, another 14.5 watt 2500 lumens also branded philips class "D"... someone enlighten me about this 😂 thanks.