I hope this shows the clips in action. I took these off a pair of suspenders I had that where to short. I have looked on the web and can't seam to find the clips. The suspenders are available from the suspender super store. I think they are call airport friendly suspenders. Basically they have a cam that rolls over and pinches the material.
In the pics below the closest cam is open and the far one is locked onto the pants.
