It is the Kupo Mitchell Thread Collar to 5/8" Baby Adapter, a durable and versatile tool designed for professional photographers and videographers. This high-quality steel adapter is innovatively designed to seamlessly convert a Mitchell thread into a 5/8 inch (16mm) baby pin, expanding the compatibility of your equipment. Ideal for attaching lighting equipment or other accessories with a 5/8 inch stud, it screws directly into the center of any Mitchell threaded collar. This stylish and reliable adapter is a testament to Kupo's reputation for producing top-tier photography and videography equipment. Whether you're a parent ensuring your child's safety with a baby carrier or a professional capturing the perfect shot, the Kupo Mitchell Thread Collar to 5/8" Baby Adapter is an essential tool in your kit.