CELLTREAT disposable Serological Pipets are manufactured from optically clear polystyrene in a class 100,000 clean room. The 1ml, 2ml and 5ml are a one piece construction and the 10ml, 25ml and 50ml pipets are made with a durable ultrasonically welded 3 piece construction. CELLTREAT pipets are printed with bold clear bi-directional graduations and markings. Graduations are calibrated for accurate dispensing to within ±2%. The pipets include color coded stripes for quick volume identification. The pipet plugs are a premium material which creates a filter barrier, performing better than standard cotton plugs.