The ThinkPad Mini Dock Series 3 ( Type 4337 ) is ideal for notebook users who need easy access to the Internet/LAN, multiple USB devices, audio and video equipment or output to dual monitor display. Note : Does not come with key for lock . Docking station for thinkpad T series . see https://support.lenovo.com/us/en/documents/migr-72871 ThinkPad L412*, L512*, L420, L520 ThinkPad T400s, T410, T410i, T410s, T410si, T420, T420s, T430 , T430S ,T510, T510i # as it is used , there could be minor scatches on underside . # Tested and is in good working condition.