Specifically designed to minimize operator fatigue, the new Portable Pipet-Aid XP is smaller and lightweight. It accepts most pipets from 1 to 100 mL. Each button has three speeds, F Fast, M Medium, S Slow. The XP is powered by a nickel metal hydride (Ni-MH) 9 volt rechargeable battery. The XP incorporates a Tissue Culture Nosepiece which features a unique filter element. The TC filter will cease to allow air to pass in either direction if it becomes wet, alerting the user to possible contamination of the rubber insert.