This kit is an upgrade to our self adjusting chuck and/or slip clutch with 3 hole sizes for the diaphragms, foam ring support insert, standard rod butt cap and zip ties. The diaphragms will hold rod butt sizes ranging from 5/16″ to 1 ¾” in diameter. The foam ring support insert is designed to go inside the self adjusting chuck prior to installing the diaphragm and will help the rod self center and support the diaphragm for a longer life. The standard rod butt cap works with our 13/16″ standard diaphragm extremely well, so consider using this butt cap on your rod during construction as a placeholder for your chosen butt cap. The zip ties are the right size to make it all fit tight.