What is this?The USB port blocker can be used in a variety of equipment and place, and is suitable for optical fiber switches, routers, industrial computers, computers and other devices with USB optical ports. The product is a blocking cap made of PP material, which can protect open network ports and easily prevent users from connecting cables, devices or inserting foreign objects without permit.What will I get?Package contains:20 x USB Port Blocker (Material: PP)Length*Width*Height: 12*10*5/0.47*0.39*0.2inchColor: BlackIs there any advantages of the product?Our products can protect data . The elastic buckle design can effectively lock the USB optical port; it is small and portable, can be put into your bag or pocket, and meets all your IT needs. Dustproof, moistureproof, waterproof and anti-oxidation.How to use it?When installing, take out the optical port lock, align it with the optical port of the device and push it in gently; when you hear a "click", it means that the optical port lock has locked the device interface; What should I notice?This product is non-removable and cannot be removed after installation,the product is simply locked and still requires care to protect the information. If you have any questions, please contact me in time, I will be happy to help you solve them.