• President Donald Trump will inspect eight border wall prototypes in California on Tuesday.
  • Only some appear to be see-through, like Trump said he wants.

President Donald Trump is set to make his first trip to California as president Tuesday to inspect eight options for his proposed massive wall along the southern border of the US – but his past statements make clear that just a handful of the walls offered would meet his standards.

When Trump tours San Diego to view the border wall prototypes, he will be presented with four solid options and four that provide some window into the other side. However, just two of the options appear to offer a clear view of the opposite side. Trump previously said, on multiple occassions, that the wall must be “see-through.”

Here are the eight border wall prototypes:

Earlier this year, Trump told The Wall Street Journal that the wall must have transparency.

"If you have a wall this thick and it's solid concrete from ground to 32 feet high which is a high wall, much higher than people planned," he said. "You go 32 feet up and you don't know who's over here. You're here, you've got the wall and there's some other people here."

"If I'm standing here, I want to be able to see 200 yards out," he added. "I want to be able to see, I don't want to have a piece of concrete that I can't see."

If the wall was not see-through, Trump said people would "have no idea who's on the other side."

"Does this make sense or am I just wasting my time?" Trump asked, to which then-White House communications director Hope Hicks interjected, saying the see-through version of the wall is "what you've always talked" about and is "consistent with what you've always said."

The comments echoed remarks Trump made to reporters aboard Air Force One in July, suggesting that the border wall needed to be transparent so that people on the US side wouldn't get hit by massive sacks of drugs tossed over it.

"One of the things with the wall is you need transparency," Trump said. "You have to be able to see through it. In other words, if you can't see through that wall - so it could be a steel wall with openings, but you have to have openings because you have to see what's on the other side of the wall.

"And I'll give you an example: As horrible as it sounds, when they throw the large sacks of drugs over, and if you have people on the other side of the wall, you don't see them - they hit you on the head with 60 pounds of stuff? It's over," Trump continued. "As crazy as that sounds, you need transparency through that wall. But we have some incredible designs."

Funding for the wall has yet to be secured.

NBC News reported in October that four of the prototypes are made from concrete while the other four are made from non-concrete materials that could be used as see-through stretches, though photos of the prototypes show just two that appear to be considerably see-through. Each prototype is between 18 and 30 feet high, the publication added.

Building a massive border wall was arguably Trump's signature campaign promise in 2016. The White House has said the project would cost between $8 and $12 billion, NBC reported, adding that the Department of Homeland Security estimates it will cost as much as $21 billion.