The DX610 Pest-A-Repel uses different sound and frequency technologies to make it more irritating to rodents.
The DX610 uses an auto-changing, high intensity frequency AND pulse sequence.
Many rodents, like mice or rats, will, in fact, either get use to, or not think it irritating enough to leave, if there is only one sound frequency (like many “copy cat”, and cheaper priced pest repellers on the market today).  You can buy a package of the cheaper repellers for under $30, but you get what you pay for.
Remember, once you discover that you have a rodent problem, you need to act quickly before they start nesting. Once that happens, it will take longer to get rid of them.
You are better off using a product that works to get rid of them quickly before they have a chance to nest.