Control air evacuation, liquid uptake, and liquid dispensing with three valves, each containing a chemical-resistant stainless steel ball. This rubber safety pipet filler is designed for efficient one-handed operation. Pinch release valve for smooth liquid flow. Filler fits standard size pipets. (Order the red pipet filler for safe pipetting of caustics. It does not contain carbon black and will not smudge.) Filler measures 54 x 54 x 130 mm.