Manfrotto | 013 Adapter Spigot
Connect it with a wide range of tripods and gripping equipment for great versatility. Its double-sided design allows you to merge two accessories at once. Its grooved center makes installation and removal quick and easy.
It is designed with a universal compatible diameter of 16 mm , and has a double outer thread with 6.4 mm (1/4") and 9.5 mm (3/8") for attachment of accessories.