The Low-Yield Nuclear Explosion Device is a smaller, more controlled version of the Manhattan Module.
While it is less powerful than the larger version, it is still dangerous and should be handled with extreme caution. It is useful when you need a more localized explosion for landscaping or clearing hostile territory without the much larger crater of a full-scale nuclear device.
It can be triggered with a redstone signal or a nearby explosion. Be warned, there's no delay between the signal and the explosion.
Danger
Even with its "low yield," the blast is significantly more powerful than standard TNT. Ensure you have properly secured the area and are at a safe distance before detonation.
There is a config setting called "Boring Nukes" which makes the device behave like a block of TNT.