Spectrophotometer Cells, Flowcell Type 584.4 with Short Pathlengths, Tall Aperture, Threaded Connectors Fully masked cell with rectangular aperture, 2 clear windows, designed for use in spectrophometers with a beam width up to 4mm, 4mm wide x 17.5mm high. The cell sample compartment must be correctly aligned in the instrument light beam. Type 584.4 range cells have long sample compartments, therefore a 15 mm "Z" dimension is also suitable in an instrument with an 8.5 mm "Z" dimension.