Shipping is free to Amazon Prime members or on orders over $35. About this item: - Real-time monitoring with 4 bottom and 2 top sensor probes for water leaks - Loud 110 dB alarm for early warning, easily silenced with a push button - 5-year total lifespan, runs on 2 replaceable AAA batteries (included) - Wire-free, sleek design for small, hard-to-reach areas with sensitive probes - IP66 waterproof rating for extended use in humid areas, durable and rust-proof.