The two attaching bolts put tension on a coat hanger type wire retainer that rests at the bottom of the barndoors main body. The wire can be hooked and un-hooked into a retaining notch. This design creates a simple,yet fast-removing system that allows you to set the tightening bolts for reflectors from 6.5 inches to 7.5 inches,which would include "many" monolights with their standard reflector. This is a 7 inch Speedotron universal mount grid reflector and a Brown Line M11 convection-cooled light head. The bottom wire retaining system REALLY grabs on well with the rolled metal edge "lip" found on the outside front rim of Speedotron 7 inch reflectors.