UUGear 7-port Hub UUGear have just released a new 7-port USB hub add-on board for the Raspberry Pi. It is an updated version of the device they released in 2014. It has the same footprint as the Pi and can be attached to all Raspberry Pi versions which currently includes Models A, B, A+, B+, 2B, 3B and Zero. Unlike most other Pi add-ons boards this product is designed to be mounted underneath the Pi which keeps the top surface free for messing about with GPIO pins and the camera interface.
Source: 7-Port USB Hub For Raspberry Pi (Raspberry Pi Spy)