This is the Siemens 6GK7443-5DX03-0XE0, a CP 443-5 Extended communications processor that connects a S7-400 to a PROFIBUS network. It handles DP master duties — but verify CPU compatibility before specifying it.
Power comes from the backplane bus at 5 V DC, drawing typically 1.3 A. That 6.5 W heat load stays within the S7-400 chassis budget, but it adds up if this is one of the maximum 14 CPs per CPU. Keep an eye on the total backplane current if you're stacking multiple CPs. Physical fit is the S7-400 single-width format: 25 mm wide, 290 mm tall, 210 mm deep. IP20, so it's for a closed cabinet. The PROFIBUS interface is a standard 9-pin Sub-D (RS485).