The Liberator ® Series of headsets offers adaptive suspension technology allowing you to easily change between different wearable configurations depending on application and comfort. The Over-the-Head (OTH) suspension system has a single, padded headband that is adjustable for different head sizes. This suspension system is used without a helmet and is comfortable to wear with hats and baseball caps. The Behind-the-Head (BTH) suspension system is highly adjustable and provides excellent stability during vigorous activities. Behind-the-Head was designed to provide enhanced comfort under ballistic helmets, including various conventional and “high-cut” helmet systems without mounting to helmet rails. BTH is the best option for additional stability or for using ballistic helmets without an interface for rails. NOTE: For use with Liberator HP 2.0, Liberator IV, and Liberator V models manufactured after 2/2021