USB-DAC or earphone with Apple Lightning connector that draw power from the the iDevice are required to use the LAM module (based on MFi design requirement). This LAM module support only up to 48kHz sampling frequency and 24-bit bit depth. Some of these products in the market may claim to be using a DAC capable of 192/384kHz 24/32-bit but in reality it can only deliver 48kHz 24-bit audio due to the LAM upstream limitation.
For this reason, ZuperDAC and ZuperDAC-S didn't come with a lightning interface so we can support true high definition audio up to 192kHz and 24-bit. The downside is that you have to use the Apple Lightning to USB Camera adapter for the connection.