Eisco Labs Red Pipette Pump 25 ml , Fast release pipetting device for precise pipetting & zip quick emptying. The knurled thumb wheel can be rotated to draw up or dispense liquids while the releaser may be pushed in for zip quick emptying. The molded chuck has a silicon rubber collect inside to hold various pipettes of standard sizes. It resists acids & alkalis and can be easily disassembled for thorough cleaning.