Peak Design Universal Head Adapter..

Use any third-party tripod head on your Travel Tripod with the Universal Head Adapter from Peak Design. Simply remove the compact ball head and replace it with a tripod head of your choice and install it with the included 4mm hex wrench. The head threads onto the adapter's 3/8"-16 threaded mount, and it secures by tightening the three set screws into the bottom of your tripod head.