We recommend replacing strings and cables at your local pro shop or through the Ravin Service Department every 2 years or after 400 shots. If you choose to replace them yourself, use only the Ravin Press. Do not use the Ravin Bow Press on any other crossbow. Be sure to thoroughly read the instructions and warnings that come with the Ravin Bow Press. It is designed for use exclusively with the R26, R26X, and R5X models.