USB A
The number of USB inputs located on the body of the card reader or hub (see “Type”). This parameter determines the number of USB ports you will have at your disposal after connecting the device. "Pure" card readers and combined models usually have 1,
2, and even
3 USB inputs, while hubs typically feature
4 or more ports.
Power Delivery
The technology allows you to work at higher voltage, thereby increasing the transmitted power.
USB hubs with Power Dlivery can not only charge smartphones faster, but also power more power-hungry devices, such as laptops.
HDMI
HDMI is the most popular of modern multimedia digital interfaces. It is specifically designed for HD content and provides the transmission of high-resolution video and multi-channel audio through a single cable.
HDMI outputs are mainly found in hubs connected via USB Type C and compatible with the Thunderbolt interface (see "Connection"). Essentially, to use HDMI, you will need to connect the device to a Thunderbolt v3 port — a "pure" USB Type C does not support video transmission. This capability may be useful if an external screen is intended for HDMI connection, but your PC or laptop lacks such ports, or they are occupied or unavailable for other reasons. HDMI can have different versions, which affects its bandwidth. For instance, to transmit 4K video at 60 fps, you need
HDMI v 2.0 or 2.1. And
multiple ports will allow you to connect more than one monitor.
Switch
The presence of a switch that allows you to turn off the power supply to the USB ports. This function can be implemented either by one
common switch for all ports at once, or by personal
buttons for each port.
USB cable compartment
A special compartment on the case of the card reader or hub (see "Type"), in which the USB cable is placed during non-working hours. Such models are compact and easy to transport due to the fact that the wire, which tends to get confused and interfere, is hidden inside the device. For objective reasons, only devices with an external connection can have
a cable compartment(see "Intended use").
Cable length
The length of the cable supplied with the device. Mostly relevant for models with a non-removable cable that cannot be replaced.
