Saumir's Twinner is an Item that can be attained while traveling through the galaxy. This upgrade generates 2 balls at the start of each of your envelopes, similar to the effect of a [N]ew Ball powerup.
This item is acquired by completing the mission Holovan Land of Peace. (Unlocked by completing 5 Free a Prisoner missions in FURI). Holovan Land of Peace is completed by exploring 100% of Holovan and visiting the spokesperson at the given coordinates.
The inventory text reads:
During the synthesis of your first drilling ball, the twinner is activated and duplicates the ball.