T1 CSU ACE 3rd Gen (T1 Channel Service Unit used for interfacing CPE equipment to a T1 line. Powered by 12 - 48VDC. AC to 12 VDC wall plug included w/ unit. Unit is transparent to ESF and B8ZS. New housing with LEDS on front of unit and interfaces on rear of unit. Must be ordered and shipped in multiples of 4)