Cuvettes come in matched pairs in standard, semimicro, or Micro size, and can be ordered with either a cover of PTFE resin or a stopper of PTFE resin. All cuvettes have a 10-mm pathlength. All pairs are accurately matched to give the same value for the same solution within 1 percent tolerance. Quartz cuvettes can be used for the entire UV Spectra down to 200 nm and have a guaranteed 80 percent transmission at 200 nm. Matched pairs for less data variability.