Hey, if you've got that RinseClean 2-Tank Spin Mop and the heads are looking worn out, this BonusLife pack is exactly what you need. You get 4 fresh microfiber mop refills plus one mop head base – basically everything to refresh your mop. These refills are super absorbent and have soft strings that won't scratch your floors, plus they're reusable for up to 3 months with proper care. They're designed to remove over 99% of bacteria with just water, which is pretty cool. Just make sure you've got the 2-tank system (NOT the 1-tank version), because they're made to fit perfectly. The triangular heads measure about 2.9 inches on the inner rim and 4.3 inches on the outer rim. Makes cleaning your hard floors a breeze again without buying a whole new mop!