This is 1/4" 1/4" Male to 1/4" Male Threaded Screw Adapter. * Made of ALL Stainless Steel, much more stronger. * 26mm diameter, much bigger than our Old Small Double Head Stud with 1/4" to 1/4" thread, so much more easier to srew onto other parts such as our Single Rod Clamp, please refer to following image * 1 pieces pack