Donald Trump’s plans to build a “big, beautiful wall” between the US and Mexico have gotten less grandiose the longer he’s been president.

In its latest iteration, the wall would span 700 of the US-Mexico border’s 2,000 miles and cost nearly $18 billion to build, according to sources quoted by the Wall Street Journal. The new specs come from a Department of Homeland Security report to some members of the US Senate.

The length is on the lower end of Trump’s most recent estimate—in July, he said it would be 700 to 900 miles—and a considerable cut from the 1,250-mile figure Homeland Security officials were factoring in February.

At that time, the agency calculated it would cost $21.6 billion to build that stretch, or around $17 million per mile. The new cost estimate comes out to more than $25 million per mile. That’s a far cry from Trump’s own projections. Last spring, he said the whole project could be done for less than $10 billion.

His initial vision of a solid, concrete barrier, as high as 65 feet at one point, has also morphed into a see-through barrier with a height between 18 and 30 feet.

Trump’s wall is again at the forefront of the immigration debate in Congress because he’s is making it a necessary condition for any replacement for the Deferred Action for Childhood Arrivals (DACA) program, which allows undocumented immigrants who came to the US as children to stay and work in the US. Its beneficiaries could become subject for deportation if Congress doesn’t pass a new law to protect them by March.

But even this scaled-down version of the border barrier is likely to face resistance. Democrats, and even some Republicans, have said they oppose the concept of spending billions of dollars to wall off the border.