There are two main types. It can be used later for warm weather activities or times when you want less weight. This type is machine washable. The second type is made of silicone. Most women prefer this style, because it is more lifelike.
Silicone is closer to the consistency and weight of a natural breast.
You may find the weight a bit tiring, but it can help balance the other breast and keep your posture straight. Silicone products are hand washable. Many prostheses are shaped to include a nipple on the front. Prostheses also come with different kinds of covers. Most have some type of cloth cover, like soft cotton.