Perfet Size: 6 Pack in the package The mop heads 13.8 '' diameter, Inner triangular rim size 4'' and the outer triangular rim size 5.9'' in diameter, compatible with ocedar for spin mop system. Attention: The mop head replacement is compatible with 1-chamber mop system only, not for 2-tank Rins Clea mop system. Durable & Reusable: Made of 100% high-quality microfiber, durable and machine washable. Just toss in the washing machine to renew the fiber and re-use! This mop head have extremely water or dust absorption and won't scratch the surfaces you're cleaning.