AVN5510 Audio/Visual Expansion options Basic high performance and built-in expandability makes the AVN5510 ideal as the heart of even the most complex system. BT-E500 Hands-Free Car KitsParrot Bluetooth® Allows hands-free operation with AVN5510 using any Bluetooth®-enabled cellular phone so incoming calls can be heard over system speakers and calls can be made with voice control over phonebook entries. iPC-106 Interface Adapter for iPod® Allows enjoying favorite music from an iPod. Also recharges when connected. iPod® is a trademark of Apple Inc., registered in the U.S. and other countries. Circle Surround II An innovative audio technology that generates multichannel sound from any audio source including CDs and MP3s to enjoy on a conventional 4-speaker system, Circle Surround II is an ideal for mobile environments as it includes two other advantages. Focus can be switched in so that the stereo soundfield is perceived to be higher and aimed at the listener(s) from the front as in home systems. This overcomes the problems of most in-car speakers that are positioned low and to the sides. TruBass, a technology based on psychoacoustics and scientific knowledge is especially welcome, allowing small speakers to be perceived as generating impressive bass frequencies without requiring a costly subwoofer. DVD Video 50W 4 FM/AM Advanced 24-bit DAC 7-band PEQ Crossover Listening Position Selector AV output for rear monitor AV input ESN Security ESN is an effective theft-deterrent feature which totally disables a head unit until a Key CD recognized by the head unit is inserted.   High voltage (5V) and low impedance output A tradition from ECLIPSE’s famous analog only audiophile products, an important factor in assuring maximum sound quality has been preamplifier outputs which put out a healthy voltage at low impedances so that amplification downstream sees an ideal signal at its inputs. The AVN units’ preamplifier output of 5V with a low impedance of 55 is just that, allowing a very high signal to noise ratio and unrestricted dynamics.