ITEM:40pcs 3.15x4.72in/8x12cm,30pcs 3.94x5.9in/10x15cm,30pcs 5.9x7.87in/15x20cm antistatic bags with 100pcs 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, IC,LED and other electronic parts 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 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 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 RESEALABLE TRANSLUCENT BAG: Our bags allow you to easily seal your products without the need for other equipment,you can easy to see the items inside,good ideal for store electronic parts, such as hard drive,memory, earphones, data cable, ect.. We also attach num matching antistatic lables for better use. Please make sure you choose the right size