Boat Hook Yarn Mop Cotton fiber strands make this an effective cleaning accessory for use in areas that require more pressure. Fits all Sea-DogA(R) boat hooks and all universal threaded devices. Universal/Acme ThreadWARNING: This product can expose you to chemicals which are known to the State of California to cause cancer, birth defects or other reproductive harm. For more information go to P65Warnings.ca.gov.