The check valve is mainly used for the unidirectional flow of fluid in the pipeline, which only allows the fluid to flow in one direction to prevent the fluid from flowing back. Features: 1.Made of high quality stainless steel, sturdy and durable for long term use. 2.With good corrosion resistance and high pressure resistance. 3.Good sealing ability prevents liquid from leaking. 4. 1/2inch standardized thread, suitable for most pipeline systems. 5. Applicable for water, steam, oils, nitric acid, urea and more. 6. Mainly used in petroleum, chemical, pharmacy, fertilizer, electricity pipelines. Specification: Material: 304 stainless steel Thread: DN25 1" Flow direction: one-way Color: silver Size (L*H): 8*6.5cm/3.15*2.56n Weight: approx. 323g/11.4oz Package List: 1 * Check Valve Note: Allow slight error due to manual measurement.Thanks for your understanding.