USB interface, universal for laptops, PC or computers, not suitable for USB 3.0. 4-digit password combination, easy to set. Easy to install and use to high security computer devices, Anti-theft. Works with all , desktops, docking stations with built in standard security slot hole. Instructions: Align the password with the on the lock body, and the code switch to the direction of the by hand, and hold it down until the step is completed (you must not let go during the setup process). Set the first password, such as 1-0-0-0, release the key switch, check whether the password is set successfully, then repeat the above steps, and then set the second, third and fourth passwords respectively. When you set the password successfully, you need to dial the password immediately to prevent garbled characters caused by accidental misuse of the code switch. Check to make the password is set and then lock it to your computer. Specifications: Type: USB Laptop Lock Used for: Most digital devices with USB holes Features: Universal, 4-Digit Password, Easy to Use, Laptop Security Cable Length:1.9m Cable Diameter:5mm() Material: alloy colour: black grey + silver Package Contents: 2 x Lock Chain Cable Only the above package content, other are not included. Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.