MX2800 DS3 AC Redundant with Fan - Unit is 19in. or 23in. rackmountable and ships with one 8-pin to 8-pin modular cable one modular to DB-9 female adapter Unit is AC powered and has an optional built-in V.34 modem for management Also has optional fans for temperature controlled environments or when more than 27 units are needed in one rack Each unit consist of a chassis one or two DS3 controller cards and one or two AC Power Supplies.