Control circuit, the pump is more stable. Great for PC CPU cooling system. Tap the marked instructions. The small 3P power connector can be connected directly to the original position of the headrest fan. Support speed test function. With a rubber base, an ultra-quiet experience. With high quality and durable performance. Flow Rate: max300L/h Head: max1.9 meters Power Connector: 3P Small Connector Voltage: DC12V Voltage: 4W Water Tank Capacity: 150ml Noise: 23DB Dimensions: About 66x56x86mm (Net Size, Excluding From Faucets,) Faucet Diameter: About 9.4mm Color: As Shown Material: ABS Packing Content:1 * Ultra-Quiet Water Pump KitOnly the above package content, other products are not included. Note: The light and different displays may cause the color of the item in the picture to be slightly different from the real thing. The allowed measurement error is +/- 1-3cm.