Fractal Harness is a rare Artifact — Equipment card from Commander 2021 (C21), collector number 388. Current market price: $2.29, TCGplayer market prices via Scryfall.
When this Equipment enters, create a 0/0 green and blue Fractal creature token. Put X +1/+1 counters on it and attach this Equipment to it. Whenever equipped creature attacks, double the number of +1/+1 counters on it. Equip {2}