The reason is that the Catchbox Lite comes with its own transmitter and receiver that work in the 2.4 GHz band. The Catchbox Pro doesn’t come with a transmitter, but instead allows you to connect your own beltpack. So there are more electronic components included with the Catchbox Lite.
The Catchbox Pro DOES NOT come with a transmitter or receiver so you need to use your own equipment. You can insert your existing beltpack into the Catchbox and use any of the 3 connectors that we provide (3.5 mm jack, 3 pin mini XLR and 4 pin mini XLR). It is suitable for larger events and its range will depend on your own system.