New Heavy Duty & Medium Duty String Mops combine the benefits of microfiber with the cleaning ease of a traditional string mop. Microfiber benefits include extreme liquid and dirt pick up as well as 96 percent bacteria reduction compared to traditional mops. Floors dry faster without streaking. Looped ends allow greater floor coverage and control and prevent the mop from tangling while laundering. Use with Unger String Mop Holder Clip or any standard mop holder and handle. Use with Unger's Dual Bucket System or any standard wringer. Heavy Duty weights 16 oz and has 32 strands, Medium Duty 11 oz, 22 strands.