FUNCTION: The 38-piece adjustable tips kit is a combination of the 5.5 x 2.1 mm universal power supply, it allows you to charge laptops from various outlets even you have only one AC charger adapter. It is also compatible with the DC 5.5 x 2.1 mm power extension cable and the USB DC 5.5 x 2.1 mm cable. With the usb to dc cable, it fits the usb mains charger. SIZE: All DC power sockets have the standard dimension: 5.5 x 2.1 mm. The parameters of each mouthpiece are all presented on the description. They fit almost all laptops. Very full. Please check before purchase if there is what you need. COMPATIBILITY: This DC connector kit is compatible with laptops and external power supply and on-board transformer. For example, compatible with Lenovo, compatible with Dell, compatible with Toshiba, compatible with HP, compatible with ASUS, compatible with Acer, etc. NOTE: NOT compatible with Dell inspiron 5558, 2017 ASUS Q504UA, not compatible with Xiaomi and other special size Pcs.