A. [DIY Quantity Setting] The water pump has a unique DIY quantity technology developed by our R&D team. In normal mode, you can press the 600ml button and automatically pump water to 600ml. Importantly, you can press and hold the 600ml button for three seconds to enter the DIY quantity mode (see the picture on the details page). B. The bottle dispenser body uses an insulated high - density ABS plastic shell, which is a suitable material for electronic drinking water pumps. It is small and portable. C. The purpose of this water bottle pump is to make life more convenient. The water dispenser combines a complex internal structure with a portable mini size. With this portable water dispenser, you don't need an expensive and space - consuming floor water dispenser at home. D. It is widely compatible. The drinking water pump is a universal water pump that can be used for 2 - 5 gallon water bottles with a universal 2.16 inch neck. E. The 1200 mAh battery (USB rechargeable) ensures 30 - 40 days of use. This water pump is suitable for home, kitchen, office and camping.