Keyence CU-21A Standard Type Main Control Unit CU-Series AC100~240V JapanThe Keyence CU-21A is a standard type main unit in the CU series. It has two inputs and a minimum input time of 5 ms. It has an external calibration input signal and a connection sensor. The input system is either a transistor (via NPN output device) or a contact.Have some marks and scratches due to old stock.© All the pictures are Organic and this part is physically in our stock