This Munchkin Reshine Replacement Brush Heads 2 Pack Gray are twist-on-brush refills for the Shine™ Stainless Steel Bottle Brush (sold separately). The quick and easy brush refill replaces your old brush head after 30-45 days of use and even better, it provides less waste because you are only replacing the brush, not the handle. Durable and sturdy nylon bristles are tough on dirt, yet gentle on baby’s bottles and reduce the dreaded splash-back when it pops out of the bottle opening! Nooks, crannies, and hard-to-reach corners are no match for the flexible brush neck, which bends and moves to get into every bottle with ease. These brushes will "steel" your heart when it comes to cleaning. Shine™ Stainless Steel Brush Bottle Brush with handle is sold separately.