Suck It is David Wallace's product idea in the episode Sabre. It is a children's vacuum which sucks up toys, teaching kids to clean up their toys. The patent for the product was purchased by the U.S. Military for $20 million, as was revealed to Andy by David himself during a fundraiser dinner in the episode Fundraiser. A slideshow on The Office's official website

David Wallace in his Suck It shirt

shows how David Wallace designed Suck It to work for a variety of purposes, including cleaning up radioactive and nuclear waste. This is possibly how the U.S. Military will use or used it.