The RE Audio BT 900.4 amplifier is the first Bluetooth integrated amp I have came across and I was pleasantly surprised. The way the amp switches between Bluetooth signal and the standard low level RCA signal is flawless. The range was over 200 feet with direct line of sight and 54 feet without line of sight. The amplifier performed at its rated specs and sounded as well as expected. This amp is a perfect solution for classic cars and hot rods that dont want to effect the dash due to the fact that you dont need a head unit! Very cool, two thumbs up.