All-angle ball joint mirrors with stainless steel mirror backs. Visual inspection of hidden areas. Double ball joint links swivel mirrors for viewing to 360° Made of tempered spring steel to move freely and hold desired position. Replaceable, plated, copper-backed, clear-view mirrors, Non-rotating inner hex rods prevent mirrors from swinging out of alignment. Insulating vinyl grip on 1PK-390G, one(1PK-390), don’t have vinyl.