The Quantum VHF is Standard Horizon's flagship model. The Quantum VHF offers DSC calling and scrambler capabiltiy to create a versatile on-board communication system. Larger rotary knobs make for easier channel selection, volume, and squelch control. A larger 3" x 1.5" LCD display makes this VHF a pleasure to use. A 4" internal speaker allows for louder and clearer audio and the PA and Fog Horn system have been boosted to 30 watts. There are several unique features to the Quantum. A Tone Control on the Fog Horn allows you to change the tone from low to high pitch, and it has the ability to receive VHF calls while still in Fog or PA mode. You can also connect up to 2 RAM+ mics giving you the capability of two and three-way communication. When connected to your GPS, the large backlit screen will display your Lat/Lon, speed over ground, and course over ground. The channel changing mic has Standards exclusive Clear Voice noise canceling technology to allow crystal clear broadcast over noisy engines and wind. The Quantum is submersible and also features NOAA Weather Channel and Alert, pre-set key for instant recall of two favorite channels, and one-button access to channels 9/16. The Quntum Class D version includes all the same great features plus Class "D" DSC. 3.5"H x 9.1"W x 6.0"D. Three-year warranty. Note: MMSID# must be applied to enable DSC function.