From LEGO Batman Wiki
|User||Robin and Nightwing|
|Powers and Abilities||Can attract LEGO pieces towards it and deposit them in a backpack.|
The Attract Suit is a suit upgrade for Robin and Nightwing unlocked in the fourth level of the game. This allows them to suck up loose red, yellow & green Lego pieces & deposit them in the Attracto machine to create new Lego objects using a vacuum backpack which sucks in air creating a suction force strong enough to lift several small lego pieces up into the air.
Upgrades can increase the suction force effectively speeding up the process and it can detect where the pieces are using arrows to show you.