Born free soft sponge bottle amp teat brush has a unique biodegradable sponge design to help clean your bottles and teats hygienically with ease the silicone based brush has soft perforated surface ideal for getting into the tights spots within the bottles and prevents any scratching within the bottle to prevent bacteria build up the sponges tips are easy to replace and once you have finished with the sponge simply dispose of it and it will degrade slowly over time