Standard Horizon - HX400 with Built-In Scrambler & LMR Programmable Channels - HX400. The submersible HX400 combines multiple features for a wide variety of users. Commercial tough construction with all VHF marine channels, optional speaker microphone jack, voice scrambler, noise cancelling microphone and 40 programmable LMR (Land Mobile Radio) channels with CTCSS and DCS signaling. The HX4000S is popular among recreational and commercial boaters. Additional features include Built in Voice Scram