All-Purpose Silver-Embedded Terry Weave Microfiber, Ultrasonic Cut, 290 gsm, 12"x12", Silver, 25-PackSilver embedded microfiber towels 12" x 12". Manufactured with Novaron, and EPA registered, silver based antimicrobial agent. Simply dampen the cloth to activate silver ions. Embedded silver yarn inhibit the growth of most bacteria and viruses in the towel within 24 hours. Retains its silver properties throughout the life of the towel, outlasting any treated cloths. Positively charged silver ions reduce the pathogen load without the use of chemicals.