This USB A to USB C Adapter cannot improve the transmission speed of your device. The transmission speed you get is up to your device's USB A Female Port. If your device is USB 3.0 A Female port, then you get the same MAX 10 Gbps speed and if it is of USB 2.0 A Female, you will get 480 Mbps.
The Type C female port has both a 2.0 and 3.0 speed depending on configuration. Simply flip your C-type plug to swap between the speed you require.
Built-in DOUBLE 56KΩ resistor in this XAOSUN USB C Female Adapter ensures safe and long-lasting charging and data transfer, over-heat protection in the QC and BC charging, more safety. Since the USB-A port does not support PD function, it cannot support PD protocol fast charging.