Optical bandpass filters are designed to transmit a specific waveband.  They are composed of many thin layers of dielectric materials, which have differing refractive indices to produce constructive and destructive interference in the transmitted light.

Scanning, OCR and imaging software is used in optical and document scanners, specialized imaging equipment, and optical character recognition (OCR) systems. Products are used to digitize, create, edit or evaluate images.

Filtration media and elements are designed to remove suspended particles from a process stream. This product area includes bulk filter media, cartridges, housing-only products, and housing and filter assemblies. 

Sequencing batch reactors (SBR) are fill-and-draw activated sludge systems for wastewater treatment. Wastewater is added to a single "batch" reactor, treated to remove undesirable components, and then discharged.