Here’s what prototypes of a U.S.-Mexico border wall look like

The construction of prototype walls along the U.S.-Mexico border is nearing completion, according to the Border Patrol in California. A total of eight wall prototypes are being built in a fenced-off area in Otay Mesa. Construction began in late September and is expected to take 30 days.

Four of the prototypes will be made of concrete, while the other four will be made of alternative materials. The models will stand 18 to 30 feet high and 30 feet long.

The agency’s San Diego branch tweeted photos of how construction was progressing.

On Wednesday, the agency tweeted that after two weeks of construction, the prototypes were taking form.

Despite the prototypes and the testing that will be conducted when they are finished, no funding has been approved by Congress yet for a border wall. The Border Security for America Act, introduced in July by Rep. Michael McCaul (R-Texas) in the House, has 70 co-sponsors and would increase funds, resources and staffing along the southern border. Democratic leaders have said they will not support a bill that funds a border wall, but have offered to pair the Dream Act with an earlier version of the border security bill, which would encourage lawmakers to study the effect of immigration enforcement and border security before allocating resources.