DealClock via Walmart continues to offer the Boss Audio Off-Road Amplified Bluetooth Sound System
with free shipping
. That's tied with our mention from a week ago and the lowest price we've seen. (It's the best deal now by $11.) It features a maximum RMS output power of 450 watts, 6.5" marine-grade speakers, 1.5" weatherproof tweeters, internal amplifier, Bluetooth, strap, and zip ties.