Features 1、Made of high quality copper material, high strength, resistant to high temperature, very durable 2、1/4inch inner thread, suitable for many machines 3、Fit for air only, not applicable to water or oil 4、This is a one way check valve, can prevent air flowback and ensures great airtight performance 5、Useful accessory for your machine, 5pcs per pack, enough for long time use Specification Features: Made of high quality copper material, high strength, resistant to high temperature, very durable. 1/4inch inner thread, suitable for many machines. Fit for air only, not applicable to water or oil. This is a one way check valve, can prevent air flowback and ensures great airtight performance. Useful accessory for your machine, 5pcs per pack, enough for long time use. Specification: Material: Copper Color: Shown as picture Quantity: 5pcs Fluid: Air Port Size: 1/4" Size: Approx. 4 x 1.6cm / 1.57 x 0.6inch Weight: Approx. 163g Package included: 5 x Air Check Valve Package List