The Quasar Focus grants you the following features:

CHARGES

This arcane focus has 4 charges (regained daily).

ASTRAL HARMONY

When a creature you can see within 60 feet of you rolls a 1 on a d20 test, you can take a reaction and expend 2 charges to cause the creature to reroll the d20 test. You can expend an additional 2 charges to grant the creature advantage on the reroll.

CELESTIAL PHENOMENA

When a creature you can see within 60 feet of you succeeds on a d20 test, you can take a reaction and expend 1 charge to cause the creature to reroll the d20 test. You can expend an additional 1 charge to grant another creature advantage on the next d20 test it makes within 1 minute.