These pipettes feature special benefits without compromising MLA quality. Built with aluminum alloy and stainless steel, the lifetime warranty ensures maximum durability and performance. Pipets are engraved with serial numbers for easy traceability and quality control. Adjust or calibrate pipettors above or below the stated volume up to ±10%. It’s like having several fixed-volume ranges in one single pipette! Easily set the volume by selecting the applicable value engraved on the plunger. Whats Included: calibration key. Calibration feature is handy for viscous solutions.