With the deadline to finish the border wall prototypes just about a week away on Oct. 26, crews have been hard at work in California to create versions of what they believe the structure should be.

The Designs

For the construction companies chosen to undertake the task, the parameters were fairly simple: Build a 30-ft. wall out of solid, reinforced concrete, The Arizona Republic reported.

Here's what they've come up with so far:

• One wall combines a concrete base with blue metal panels.
• Another begins with a wide concrete base that narrows as it rises.
• A third design features see-through areas that give Border Patrol the ability to watch activity occurring on the other side of the wall. The ability to see through the wall was added into the Trump administration's requirements after a suggestion from U.S. Customs and Border Protection.
• One prototype includes narrowly-spaced metal bars on the bottom half, similar to traditional border fencing, with concrete panels on top.
• Arizona company, Fisher Sand & Gravel, finished their design within a few days. It features three concrete frames that slope up on the U.S. side of the border, but stand vertical on the Mexico side.

According to officials, the prototypes will undergo a series of tests before any are chosen for the border. The final design could be made up of the best elements from multiple prototypes, The Arizona Republic reported.