Bathmate are the leaders in penis pump technology. The first to bring water based penis pump technology to the market, Bathmate are still the market leaders today and offer a wide range of sizes and accessories in their extensive hydropump range. What is a Hydropump? Basically a penis pump that is used filled with water. The water creates a vacuum and safety mechanism that encourages maximum size gains, while preventing injury from aggressive over-pumping which can happen using air pumps. Bathmate are not the cheapest, but in our opinion, for durability, comfort and impact they are worth it.