The EK-XTOP DDC 3.2 PWM Elite Acetal is a high-performance water cooling pump. The core of the unit is the market-proven EK-DDC 3.2 PWM water pump (4-pin PWM FAN header) and comes pre-assembled with the EK-XTOP DDC - Acetal and EK-DDC Heatsink Housing. The PWM control allows for automatic pump speed regulation depending on your CPU temperature. Full performance on demand or whisper quiet operation in idle mode!