Correct, this is an M-LOK.
The "Expert" is incorrect. I own one of these and it is not M-LOK compliant. You have to buy special picatinny rails that screw on and then you can mount accessories to the rails. Leapers does make a version of this that is M-LOK and KeyMOD compliant. Here are the model number respectively. MTU015SSM (M-LOK), MTU015SSK (KeyMOD).