Salt Spray-Proof ASTM B117 salt spray (or salt fog) corrosion test simulates harsh conditions in a salt water environment to ensure the product does not corrode or fail in these harsh conditions. UV Protection The unit cover satisfied ASTM D4329 UV resistant test. Vibration Resitant 3-axis multi-freqeuncy vibration tested to withstand damaging shocks. Conformal Coating Improved moisture resistance of the circuit boards to prevent corrosion. Playable USB Files Compatible with a broad range of audio file formats from FLAC and MP3, WMA and AAC. 13-Band EQ 13-Band equalizer gives optimal tuning enhancements for the listener. Independent Subwoofer Volume Control allows you to easily adjust your subwoofer volume.*The volume works when the SW RCA Output is connected to amplifier/Subwoofer. All Weather System EXPANSION Ready The KMR-M300BT has RCA outputs to expand the system to connect amplifiers to power additional speakers & subwoofer(s). 2.7" LCD Display 2.7" LCD display secures higher visibility under sunlight and daytime use. Rear View Camera Input Support KMR-M300BT is equipped with a rear view camera input. With an optional camera connected, you have increased safety while driving UTVs, boats, etc.. SiriusXM Radio Ready Access additional music, sports and entertainment content on the go with SiriusXM Radio.(Optional SiriusXM tuner required, sold separately) 3” Gauge-Style Mounting 2.7” LCD Display AM/FM/Global Weather Band Tuner Waterproof Rating of IP66 Wired Remote Ready (KCA-RC35MR, Sold Separately) SiriusXM Ready® Rear USB Port w/ 1.5A Charging Variable Color Illumination Bluetooth® Streaming Rear View Camera Input 50W Watts x 4 3 Pre-Outs (2.0V)