This is a review program that includes 3 sizes of antistatic bags, perfect for individual buyers, saving you money, but please be sure to review it, so easy, thank you!. MOISTURE RESISTANCE OF CLASS II:High quality sealing belt reusable, with high sealing performance, waterproof and dampproof,it have a moisture resistance of Class II, it also can be vacuume to prevent oxidation of electronic components. SAFETY ENVIRONMENTAL PROTECTION: We bags made from high quality Polyethylene Terephthalate (PET) with an aluminized film, high and low temperature performance of ±500c, non-toxic and eco-friendly, no odor. HIGH ANTI-STATIC COEFFICIENT:The internal and external anti-static coefficient of the bag is above 10th, which is higher than the 8th to 9th power of the same industry. This must be the product you need. ITEM:10pcs 3.15x4.72in/8x12cm,10pcs 3.94x5.9in/10x15cm,10pcs 5.9x7.87in/15x20cm antistatic bags with 30pcs antistatic labels, MULTI-USE: 3.15x4.72in for 1.8" hard drive, 3.94x5.9in for 2.5" hard drive, 5.9x7.88in for 3.5"hard drive. them also can be used for RAM, I/O memory card, earphone, button battery, and other electronic parts.