3M 311 1254 E A R Disposable Corded Ear Plugs, Bullet, 33 dB NRR, 200 PK G2848157 Amps 20 A Enclosure Rating Amps 20 A Enclosure Rating NEMA 3R Color Black Number of Conductors 3 Housing Material PVC Hz 60 Hz Hz Type Line Cord Plug Style Straight Standards UL Listed Trade Designation SJTW Self Testing Yes Trip Level 4 to 6mA Current Amperage Rating 20 A Conductor Type Copper Connectivity Plug In Strands Multi Series Extra Heavy Duty Amperage Rating 20 A Item Type Straight Blade Style Manual Set Current Rating 20 A Industry Standard(s) UL Listed Construction Fabricated Application Line Cord with Male Female Ends Temperature Rating 35 Degrees C to 66 Degrees C ( 30 Degrees F to 150 Degrees F) Voltage Rating Description 120 VAC Material Jacket PVC Material Insulation Elastomer Country of Origin China and cosmetic finishes so that the entire setup looks and functions consistently as a family