CA - H4 Hytera 13 PinIntelligent Architecture Constant Able PTT Hytera 13 Pin (H4) The most capable, broadly compatible Push to Talk for two way radios on the market. Developed with SRT and SWAT operators to tackle the toughest interoperability challenges. Auto Sensing The Intelligence Core Push to talks arent just an accessorytheyre the core of comms. The Constant Able uses embedded proprietary algorithms to decide, rewire, and adjust gain within 100ms. Microphone