Rad Defender System

The  mod can be attached to certain Masks to enhance protection against radiation exposure.

Advanced Rad Defender System
The concept behind these gas mask upgrades, is they are very useful, but you don't want to wear it all the time. The design of the Defender System is to provide high rad resists while allowing you to wear your regular armor. NOTE: Be careful not to build the same rank twice by accident, as it will do nothing
 * Advanced Rad Defender System: This slot can be upgraded 5 times (+50-400 Rad Resistance based on rank)
 * The Defender system does not remove rad damage you already have, it simply helps to prevent further damage to your body
 * The Defender system reduces your AP refresh while wearing it (-40% to -80% based on rank)*
 * The Defender system mods have a very unique crafting feel to them, with a progressive flow that requires different skills and recipes
 * Each rank (above 1) requires the previous rank's loose mod
 * To upgrade each rank, choose the standard mod to eject the current mod, exit the workbench, and then build the next rank with it**

*I may make a better debuff system in the future, but I don't want to add more to the patch right now

**The loose mod requirements won't update properly unless you exit/enter the workbench again

Mods
Adding a cleansing system will greatly reduce radiation exposure, but comes at a cost.