Performance™ 4 Pieces 33 mm Spray Gun Locking Collars by 3M®. The unique 3M™ Performance Spray Gun Locking Collar helps ensure a solid connection between the 3M™ Performance Spray Gun and 3M™ Performance Atomizing Heads. The locking collar is easy to use, allowing for quick nozzle changes while switching between paints and coatings or for cleanup at the end of a job. The easy-grip tabs make it easier to turn the locking collar.