100% Continuous Filament Polyester, Knitted, Laundered, 9"x9" (23x23cm) Berkshire Super Polx® 1500 is a knife-cut, cleanroom laundered wipe recommended for controlled environments rated ISO Class 4 and above. It is composed of 100% continuous filament polyester knit fabric. This combination of properties provides Super Polx® 1500 with high level of cleanliness, abrasion resistance, and chemical compatibility.