Resealable, 15x20 cm/6x8 inch, 50 pcs packing. | Resealable ESD bags are made of PET 3 layer composite material, brand new CPP and electronic plating aluminum, no toxic material, can prevent static electricity very effective. | Surface Resistance(inner & outer) is 10^8-10^10(Ω), thickness is 0.15mm(double sides). | The antistatic ziplock bags are very good for waterproof and dustproof, can be open & close many times, for long terms storage. | Thank you for choosing & trusting us and we would be really appreciated if you could share any reviews about our product being used. :)