20″ x 30″ 4mil Cleantuff Poly Bags, Class 100 Size is ID, Width X Length in Inches. Cleaned & Certified to IEST-STD-CC1246D, Level 100. Supplied with Certificate of Conformance. Volume price breaks are available. Please contact us for pricing on quantities over 2000 bags. Price listed is per 100 bags. 4mil Cleantuff Poly Bags and Tubing offers the strength of 6mil materials at the more economical 4mil pricing.