Historical Rules · 7 August 2020
Rule 702.42a
Official source text from the 7 August 2020 Rules release
Modular represents both a static ability and a triggered ability. “Modular N” means “This permanent enters the battlefield with N +1/+1 counters on it” and “When this permanent is put into a graveyard from the battlefield, you may put a +1/+1 counter on target artifact creature for each +1/+1 counter on this permanent.”