Sonim Heavy Duty Rugged Metal Clip Cases, Perfect for electricians, police, plumbers, HVAC workers, Construction Workers, outdoors workers, EMT, Firefighters, Landscapers and more tough job requirements. If your job requires the strongest cell phone case made on the planet then we have what you need. Our rugged steel clip line of cases will hold up to the toughest jobs you can imagine. The cases are made of the finest materials including ballistic nylon and genuine leather. All Clips are removable and can be interchanged with Duty Belt clips as well.