Infrared induction delay switch.
It is difficult to say which one has the highest sensitivity. The principle is to sense the heat (infrared rays) emitted by the human body or a heat source to work. Generally, it will take action when the temperature of the sensed body is more than 3 degrees higher than the ambient temperature.
You require high sensitivity and don’t know what you want to use it for?
Whether the switch will turn on depends on the sensing range of the switch, the movement speed and size of the heat source, the surrounding ambient temperature and brightness, etc. These conditions can be adjusted for many switches.
If you want to sense the human body, it doesn’t make much sense to be sensitive, as long as you choose the right one and the quality is decent. If you want to use it to catch mice, then you really need to choose a top-quality switch!