These are necessary: a terminal, an adapter bolt 3/8 inch to 1/4 inch, any spherical head and of course, the Action Cam.
An adapter bolts 3/8 inch to 1/4 here (386BC) is included, the Amazon product description is silent but for this. In the 7 euros cheaper version (386B) no adapter is. Depending on how the adapter bolt screws into the terminal, you can connect accessories inches either 3/8 or 1/4.
Amazon is a maximum tube diameter 33mm and a maximum weight of 4kg. In fact, the terminal fits tubes up to 38mm and in the enclosed instructions, a maximum weight of 5.5 kg is indicated.
The terminal itself is made entirely of metal, very robust and holds bombproof, as usual from Manfrotto! The pliers are provided on the inside with rubber surfaces, so that painted pipes are not scratched.
Action Cam including outdoor enclosures and mini ball head (Manfrotto 492) together weigh 400 grams. This makes the terminal even when off-road driving with hesitation. In the manual, the speech of a maximum load of 5.5 kg, and in fact, makes the terminal the impression that they could easily carry a medium sized ball head with DSLR.
The module has a 45 euro initially relatively expensive. But it is also not to be compared with my initial experiments with bending Gorillapod tripods on the handlebars or other Action Cam plastic holders that wiggle, break or tilt in the first curb, including the camera all. If you consider that my 15 year old, Manfrotto ball heads still work as the first day, the Manfrotto clamp is certainly the better investment.
The terminal receives full five stars!
If there was a way to assess the Amazon product description, would get this zero stars.