SCREWS For adding more screws to your lens plates you can use our product IS ¼. The IMPETUS screw has hex socket head that is easily installed with hex key. The screw rests freely in the slot but doesn't fall out. BRASS REDUCER BUSHING - IRB If you need  to reduce thread of your lens feet from 3/8“ down to ¼“ you can use the IMPETUS Brass Reducer Bushing IRB to fastern your lens plates.