Designed for use with your No Spill Clean and Fill Aquarium Maintenance System, the Python Hook delivers a hands-free, spill-free experience every time you refill your aquarium. It literally "hooks" onto your aquarium (whether framed or frameless), to ensure that every drop of return water ends up inside where it belongs - and not on your living room floor! The user-friendly Python Hook is designed for effortless installation and use. When it's time to refill your aquarium, simply remove the gravel tube from your No Spill Clean and Fill and replace it with the Python Hook. The internal threading ensures a perfect pairing, while the integrated o-ring provides a reliable, water-tight seal. Designed to withstand the test of time, the Python Hook features ultra-durable construction. This value-adding accessory is manufactured using only the highest quality, American-sourced materials (HDPE or High Density Polyethylene). It is completely free of arsenic, BPA, and lead. Proudly made in the U.S.A. Get yours today - you'll be HOOKED in no time.