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