Prototypes of President Donald Trump's border wall were delivered last week and will undergo extensive tests to ensure they can withstand harsh conditions.

Workers will test the prototypes using sledgehammers, torches, pickaxes and battery-operated tools in order to determine their strength.

The testing is expected to last up to two months and will attempt to answer questions such as whether the wall can be climbed or dug under and if it can withstand cutting tools, ABC reports.

Each wall is 30 feet tall and is made of materials including concrete to prevent people from seeing through it. One standard requirement given to all contractors competing for the ultimate contract is that the walls are made to be “aesthetically pleasing” from the U.S. side. However, depending on the test findings, the outcome could end up being a complete redesign or merger of several of the prototypes.

The first installment of the wall is expected to cost $1.6B and if approved, will be stationed in San Diego and along a 60-mile corridor in Texas’s Rio Grand Valley. The Department of Homeland Security anticipates the final cost will be closer to $22B.