This document provides an overview of Photon Instruments' product catalogue, including humidity, temperature, pressure, flow, and gas measurement instruments. It lists several brands that Photon Instruments represents, such as Rotronic, E+E Elektronik, Sensocon, and Kimo. The document then describes several of Photon Instruments' own product lines for humidity and temperature measurement, including data loggers, transmitters, indicators, and handheld devices. It provides details on specifications and features for select models.