The product is a sensor assembly designed by CROWCON for detecting Propan gas. Specifically, it is the CROWCON XGARD sensor assembly for Propan gas, with the model number VQ21T S011523/S. This sensor assembly is likely used in industrial settings for monitoring and detecting the presence of Propan gas to ensure safety and compliance with regulations. The CROWCON brand is known for producing reliable gas detection solutions, making this sensor assembly a trusted choice for gas detection needs.