For hygiene reasons, experts recommend that you switch the sponge of your Colour Switch Solo after every 2-3 months. And the simplest, easiest and most affordable way to do so is to use this Solo Refill. As time passes, heavy usage can wear off the sponge. Hence you have to replace it with this refill in order to retain the usefulness of the fantastic Colour Switch Solo.
The sponge is just as resilient and effective as the original. You can use both sides of of the sponge and clean it with warm water and hypo-allergenic soap to use it again. It's as simple as that!