NE556N frequency conversion chip combined with ZL3840 high frequency horn that emits sound at a frequency between 22KHZ to 50KHZ, which will drive pests crazy and keep them away. Note: This product is based on physical method, it usually takes 1-4 weeks of continuous use to show its effect: rats, mosquitoes, cockroaches, etc. will be significantly reduced. In some areas, rats and cockroaches will be more active and running around within the first 3-5 days. This is normal because ultrasonic and electromagnetic waves can cause neurological disorder to rats, mosquitoes, and cockroaches. This product has no adverse effects on the human body, please rest assured to use! Instead of killing pests, this product can only drive them crazy. Therefore, it is recommended to use other mouse traps to achieve better control results. Specifications: Material: ABS Color: White Chip: NE556N Frequency Range: 22~50 #xff08;KHz #xff09; Rated Voltage: 100~240 #xff08;V #xff09; Rated Power: ≤3 #xff08;W #xff09;