100 ESD Anti-Static Shielding Bags, 15"x20" in ,Open-Top, 3.1 mils Static Shielding Bags Four-layer construction offers excellent protection from punctures and tears. Thickness : 3.1 mils Bags are printed with StratoGrey and ESD Warning symbol Testable to industry standards. This transparent, metal-in static shielding bag is designed to provide a static safe environment for sensitive electronic devices. With offer same day shipping for several stock sizes. ESD bags remains the bag of choice for IC and PCB protection. These bags are tested to meet or exceed the electrical and physical requirements of MIL-PRF-81705 Type III, ANSI/ESD S541, EIA 625, MIL-HDBK-263, MIL-STD-1686, and ANSI/ESD S20.20. Bags are RoHS Compliant* and lead-free**. PINK POLY BAGS vs. STATIC SHIELDING BAGS: Shield bags provide the dissipative and antistatic attributes of the poly bag but add a metal shield and polyester dielectric to stop static from entering the bag. The test for shielding demonstrates the difference between the various bags. Shield bags will generally stop 97% of a 1000 volt static pulse applied to the outside of the bag from reaching the inside. Pink poly will stop only about 10% and black poly about 30%.