The EPC-CM4-70 features two TF card interfaces, two USB connectors, and one LAN connector. It also has two RS232 channels, one RS485 channel, and eight Opto-Isolated GPIOs.
Concerning audio, it has one 3.5mm audio connector, one 2W internal speaker, and one Buzzer.
Please note that the 4G/LTE module does not come with the product by default, but can be added. Use the menu in the top right corner of the product page to add this module if you need it.