Question about Voltcraft Energy Cost Meter

Why does Digitec only give a 2-year warranty, while Conrad gives a 3-year warranty? Voltcraft's warranty conditions also confirm 3 years: https://asset.conrad.com/media10/add/160267/c1/-/de/VOLTCRAFTWT00/garantiebedingungen-2587316-voltcraft-sem5000-ch-energiekosten-messgeraet-kostenprognose-alarmfunktion-stromtarif-einstellbar-datenloggerfunktion.pdf