MacStick Premium Ports Thunderbolt 3 compatible port located on the very top USB C port. (charge your laptop, output video, or transfer data up to 40gb/s) Second USB C data port (ONLY FOR DATA. Does not charge the laptop or output video) Micro SD + SD card reader 2 USB 3.0 ports (transfer up to 5gb/s. Charge devices up to 1.5 A of power)** NOTE: Apple Superdrive is not compatible. All other external DVD drives are compatible. NOTE Please insert all the way! Should be no gap. Should not be loose. HEAR and FEEL a *CLICK* when inserting. It will be very secure into the both USB C ports. Apple Superdrive is not compatible. All other external DVD drives are compatible. *One USB C port is a Thunderbolt 3 port which does it all (charge laptop, transfer data, video output). The other USB C port is DATA ONLY (does not output video or charge the laptop) **USB port will charge devices at a slower rate than charging directly from a wall outlet. PREMIUM: Only for Apple MacBook Air 2018 – 2019, MacBook Pro 2016 – 2019. Compact HIGH-GRADE Aluminum body with versatile ports for all your needs. THUNDERBOLT 3 PORT (top USBC port): Charges laptop up to 100W. 5K@60Hz video output for Ultra HD. Transfers data up to 40Gbps. The 2nd USB C port is for DATA ONLY transfer up to 5Gbps.