Construction is well underway on eight prototypes for President Donald Trump’s long-promised wall along the US-Mexico border.

Several of those prototypes are “taking form or are near completion” after two weeks of construction, the US Customs and Border Protection’s San Diego bureau said on Twitter.

The government selected six companies to construct the prototypes, which the agency said are meant to “inform future design standards” for the wall.

Although Trump’s plans for a border wall have been beset by a number of obstacles — including the Senate’s refusal to green-light a $1.6 billion down payment, wavering estimates on the total cost, and a lawsuit from California — his administration has moved ahead with the prototypes.

Here’s what they look like so far: