The threads form a tight connection when fully screwed in, and we recommend that you wrap the threads with sealing tape before use, as this reduces the chances of air leaks, even if they are not fully screwed in. For a wide range of air tools and equipment requiring a 1/4" NPT connection. For automotive, industrial and DIY applications that require a fast and reliable air connection. Ensure that the male air fitting is securely attached to the 1/4" connector of the tool. Check for any air leaks or loose connections before operation. Regularly check fittings for wear and replace as necessary. Before purchasing a product, check that your connector size is 1/4" and I/M/D. Our products are designed to fit 1/4" and I/M/D connectors only. Made of sturdy iron with nickel-plated finish, quick connector air coupler is durable, wear-resistant, rust-proof and corrosion-resistant, and can be used for a long time.