Hello, Our product was 316L Steel. It is not affected by substances like liquid soap, dish detergent, shampoo, shower gel :) You can use it in the shower or in the pool. However, we recommend that you do not allow long-term contact with substances such as bleach and degreaser. You can think like our hands. Just like when you apply too much with abrasive substances, it causes irritation. Likewise, the coating wears off as you use it for a long time. Other than that, there will be no darkening or fading :) We wish you pleasant shopping :)