Very small and the resolution is not the best.
Fast shipping and delivery. Device is surprisingly compact. No documentation. No apparent switches or external interfaces besides a usb port by which the device is powered by 5v DC. It isn't obvious how to set the various modes/options asserted in the description. The description also mentions an external I2C interface, access to which is also not obvious. Even very brief documentation of the location of all interfaces and how to set various operational modes would be very helpful.