Most ATV and marine receivers can't put out enough power on their own to be heard over all the wind and engine noise. A good way to beef up your sound system is to add the NavAtlas 4-channel BMA476BT amplifier, which can blast out 75 watts RMS to each of your speakers, ensuring you'll hear it all loud and clear. If you want even more impact, you can bridge the amp in 2-channel mode and power a couple of speakers with 140 watts RMS each. You can stream music directly from your smartphone to this amp by way of its wireless Bluetooth input, so you won't even need a radio in order to play music. This version of Bluetooth supports high-definition audio, so your music will sound as good as it possibly can. This compact, water-resistant power pack fits almost anywhere — its Class D design keeps it running cool, even when it's playing hard. Features: 4-channel marine/powersports amplifier 75 watts RMS x 4 at 4 ohms (98 watts RMS x 4 at 2 ohms) 140 watts x 2 bridged at 4 ohms CTA-2006 compliant Class D amp technology Built-in Bluetooth 4.0 supports high-definition audio streaming (does not support hands-free phone communication) Variable high-pass filters (35-250 Hz, 12 dB/octave) on front and rear channels Water-resistant chassis (IP66 rated) Preamp inputs Fuse rating: 30A x 1 Wiring and hardware not included with amplifier (10-gauge power and ground leads recommended) dimensions: 11-5/8"W x 1-5/8"H x 3-5/16"D Includes: 4-Channel amplifier 40" Antenna wire Antenna (for Bluetooth) 4 Machine screws 4 Self-tapping screws 4 Washers Hex-key Installation Manual Owner's Manual VEHICLE FITMENT Universal