This is a solar powered device that uses pulsing vibrations to repel snakes, moles and voles. The pulsing vibrations are unnerving for snakes and other small animals, which are very sensitive to movements, making them believe danger may be near. Snakes will avoid the perceived danger and move to another area.
Being solar powered this may not be effective if you have 3 consecutive cloudy days. It is recommended to install 2 devices every 30m to repel rodents, which are less sensitve than snakes.
We found the Vktech effective against snakes in most circumstances. It's important the spike is firmly inserted into the soil so as to make a good contact for transmitting the vibrations. Your results may depend on the soil type in your area. Losely packed soil will not transmit the vibrations well.