. Thread Adapter with female 1/4" thread to male 3/8" thread. It is made of metal. . It works with our Double Head Stud w/ 1/4" to 3/8" thread, and make it work as a Double head stud w/ 3/8" to 3/8" thread. . Net Weight: 16g . Package Size: 105x70x4mm . Package Weight: 17g