1 Set 34pcs Multi-function DC Plugs for AC Power Adapter, All Female Base are 5.5*2.1mm. Used for external power source and on-board transformer, it is Universal Laptop NoteBook connectors. Compatible Models: Lenovo, 4-hole Toshiba, 3-hole Dell and most Laptops, Notebooks. Plug male diameter outside/inside(or pin). Note: NOT COMPATIBLE with Mac, 2017 ASUS Q504UA. Note: Please kindly check the jack size in the product description and picture, make sure this adapter tip you need is included!