What is kind of mask do the green lantern wear?

Green Lanterns don't wear masks. They wear helmets, which are an integral part of their power ring and are designed to protect their identities while providing a connection to the ring's power.

Here's why it's important:

* Protection: The helmet shields the Green Lantern from harm, particularly from the energy blasts of their weapons.

* Power Focus: The helmet acts as a conduit for the Green Lantern's willpower, focusing their energy and amplifying its effects.

* Identity Concealment: While many Green Lanterns wear their helmets as part of their personal costume, it also serves to protect their identities, especially when they are operating in secret.

So, it's not a mask, but a technologically advanced helmet that plays a crucial role in the Green Lantern's abilities and identity.