This Inside Back Plate is a replacement plate. It secures the BIS Grooming Clamp to the trolley. From the outside of the trolley, position your clamp over the section of trolley bars where you want the clamp, then insert the plate onto the clamp stem from the inside of the trolley. Securely tighten the female knob onto the clamp so that the clamp does not move up or down. The grooming arm clamps are designed to be used on the opposite end of the trolley handles, in front of the folding hinge. If the clamp is placed in the correct position it is not necessary to remove your clamp from the trolley when folding the trolley. See photo.