ET Enterprises Limited specializes in manufacturing and supplying photomultiplier tubes and electronics under the Electron Tubes brand. The company has a long history dating back to the 1930s and is a major international supplier of low-level light detection devices and systems. They offer a wide range of high-quality photomultiplier tubes, photodetector modules, and associated electronics, supported by technical and application assistance. Additionally, ET Enterprises operates a technical glass manufacturing company, Plowden and Thompson, in the UK. As a subsidiary of Ludlum Measurements Inc., Texas, the company benefits from combined resources for production and development, distributing ADIT brand photomultipliers outside the US.