Rubi Replacement Sponges for Grout Cleaning Systems Features Interchangeable sponge system with Raimondi or Siri 12" x 5-5/16" x 1-1/2" sponge makes cleaning quick and easy! Plus, the Sponge lasts longer To clean the excess material from joints High absorption sponge, longer lasting Rubi SuperPro Sponges Applications Brown Sponge for hard surfaces, all sanded or unsanded grout Yellow Sponge for all surfaces, all sanded or unsanded grout Yellow Cut Sponge for all surfaces, all sanded or unsanded grout Cellulose/ Epoxy Sponge for all surfaces, sanded or unsanded Epoxy Grout Cut the sponge and pick up more sand YellowSpongee is softer than brown Cut sponges have better performance on smooth surface tile