Modern Aquarium Substrate Flattener w/Teeth is designed with two jobs in mind;
1 - Help even out unplanted surface areas in your aquarium while keeping it naturally looking.
2 - It is important and recommended to disturb and "rotate" the sand when performing water changes. Natural processes in your fish tank can cause occasional methane build up under the upper layer of your sand. It is not a concern for those using gravel as their substrate, since the larger grain allows for those gasses to escape, but for those using sand, it is important to know that rotating the sand's upper layer right before water changes will release any trapped gasses (not visible to the naked eye) out of the aquarium, instead of polluting it and potentially harming your fish.
This flattener and all of its components are made of professional-grade stainless steel to esnure uncompromising durability and workmanship.