The FX5-16EX/ES is a 16-point discrete input module from the Mitsubishi MELSEC iQ-F series, designed to expand the I/O capacity of an FX5U CPU. It draws 100 mA from the 5V internal bus and 85 mA from the 24V sensor supply rail, so factor that into your backplane power budget when stacking multiple modules.
How it fits in a panel
Mounts on the FX5U expansion bus directly to the right of the CPU or another extension module. Occupies 16 points in the I/O address map.