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 percent . 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.