This isn't the massive $5 billion southern border the president has declared a national emergency over.
Rather, it's a 20 mile section in the Santa Teresa section of the border in New Mexico that was finished on January 30, 2019, ahead of schedule.
Customs and Border Protection says the $73.3 million project, announced in April 2018, replaces a smaller fence seen in the before and after picture above.
The aim of the fence is to prevent vehicle crossings.
It’s 18 to 20 feet tall, depending on the terrain.
You can see video of the new wall by clicking on the link from President Trump’s tweet.
We have just built this powerful Wall in New Mexico. Completed on January 30, 2019 – 47 days ahead of schedule! Many miles more now under construction! #FinishTheWall pic.twitter.com/TYkj3KRdOC
— Donald J. Trump (@realDonaldTrump) February 20, 2019