Squonk mods are devices designed to be used with a Rebuildable Dripping Atomiser (Or RDA) that is available with a Squonk pin. The huge success of these devices has led to a new breed of RDA's known as RBFA's (Rebuildable Bottom Fed Atomiser).
The device has a large capacity bottle inside the device that can hold e-liquid. When your atomiser gets dry, rather than drip more liquid into it, you would just give the bottle a squeeze forcing liquid up to the coils and re-soaking your cotton.
Squonk devices are available in regulated and mechanical.
Please DO NOT buy a mechanical device unless you are capable of building coils, understand ohms law and battery safety.