This is an automatic drip irrigation system from the brand Blumat used indoor in a growtent. It works with gravity so no electricity needed. When the soil (or other medium) becomes dry a valve will open and the dripper will work untill soil is saturated enough with water, then it shuts off again.
It works really well but can take some effort to finetune. Once it's set you dont have to water anymore.
This irrigation system works with soil and coco but the sensors might malfunction when to much perlite is added. (It creates dry spots in the medium)
You can't use mineral nutrients with this system so only for natural growers. But for mineral growers it will work as an emergency solution tho. But long term the lines might become blocked.
There is much debate about wet/dry cycles vs drip irrigation. But in my opinion drip irrigation is better then wet/dry cycles because you keep it perfectly moist all the time. Because if wet/dry cycles where really beneficial for cannabis, why would hydroponics outyield everything? Roots are always standing in water with hydro... It's because there is no such thing as overwatering. Plants wilt because of a lack of air thats being pushed away in your medium by the abundance of water. So the water only kills them indirecly. That's why aerated hydro systems are doing so great.
For more information about this system check this video:
Or you can order one here:
https://amzn.to/2SD65VK