You are buying a smooth and polished shiny stainless steel collar with a removable O-Ring at the front. When the O-Ring removed, this collar looks like a simple choker.
This collar secures with a small hex screw that is integrated into the locking tab on the side opposite of the hinge. The collar locks when the hex screw is screwed into a small grove on the lower portion of the locking tab, thereby preventing the collar from opening.
The collar can be removed by giving the screw 1-2 turns with the included hex key. Please do not fully remove the hex screw, as re-inserting it can be a pain & it can easily be lost if dropped.
Please be extremely careful when closing the collar. The hinge has the potential to pinch as you are closing the collar.
Actual interior circumference may vary by ~2mm (smaller or larger), as these are made by hand. If you are unsure of the size, we recommend ordering the larger of the two sizes.