It says in the description that the product includes a 12V-18V DC power supply, so that seems to imply that the power supply will need AC to power it to generate the 12V-18V DC power. And the picture of the receiver looks like a typical AC powered receiver, not a small battery powered camera mounted receiver.
For $115 for two transmitters, two lavaliers and a dual receiver, this system is likely to be junk. So if your expectations are low, they might be met. Expect, even under ideal circumstances, a strong hiss in the system. If there is electrical or other radio interference, expect static and dropouts.
In most audio equipment for video, you get what you pay for. Generally, the lowest end equipment that would be reasonably reliable for serious use would be something like the Sennheiser EW series.
I'm just trying to be realistic here - if your expectations are low for this low end equipment, then it might be worth spending the money.