This is a twist lock clip that's made for cases and holsters. It consists of two parts: a mounting bracket with a unique tabbed post and a patented clip ( that attaches to a belt ) with a slot that is specially designed so when you slide the clip onto the bracket and twist, it locks in place. When using this on a holster or case, the way the swivel works is that the case must be turned upside down to remove it from the swivel belt clip and can be inserted back in any direction. Using this extremely useful clip easily provides the ultimate in convenience, security and functionality! Great for making law enforcement gear, two-way radio cases, etc.