Consider this to be a review of the Tenga egg in general. There are two different degrees of stiffness of the material. Softer and "strong". I like them both. Different textures provide different sensations, all very pleasurable. They are sold as "disposable" however I have several that are more than two years old. They are easily washed with warm water and soap. Just dry with a towel and put back into the egg container. They do develop some yellowing of the material and also black spots that looks like mold. What ever the black spots are, they don't clear up with bleach. At some point just toss it/them away and break out a new one.