UPGRADED PETG DURABILITY: Our pool is 3D printed using PETG material. This food-safe plastic is highly heat-resistant (safe for warm tanks) and offers superior impact strength to prevent bubbler nozzle breakage. BUILT-IN BUBBLERS FOR HUMIDITY: Instantly boost your crabitat’s humidity levels. Each pool features an integrated bubble bar connector compatible with standard aquarium air tubing. The aeration keeps water fresh longer and creates a stimulating environment your crabs will love. (Air pump not included). NO MORE CONFUSION (SALT VS FRESH): This 2-pack includes clearly labeled designs to ensure your pet's safety. One pool is permanently marked for "Salt"，making tank maintenance easy for pet sitters and children while ensuring your hermits get the minerals they need. SAFE EXIT RAMPS & ANTI-TIP DESIGN: Designed with the safety of molting and small crabs in mind. The built-in textured stairs provide an easy grip for climbing in and out, preventing drowning risks. The wide footprint ensures stability so enthusiastic diggers won't tip them over. PERFECT DEPTH FOR SUBMERSION: Each pool holds approx. 1.5 cups of water with a 1.5” depth, allowing hermit crabs to submerge their shells to replenish shell water—a vital requirement for their gills and overall health. Upgrade your hermit crab’s home with the pool set designed for longevity and health. We upgraded our 3D-printed pools to PETG, ensuring they never warp in warm habitats or crack during cleaning. This set of two (Fresh & Salt) features built-in bubbler attachments to maintain vital humidity and easy-climb ramps for safety. Give your crabs a colorful, durable, and functional swimming area that mimics their natural environment.