Tetra SB 45 contains two stainless steel replacement blades for the simple and reliable Tetra aquarium glass scraper. For optimal cleaning results, it is essential to always use a sharp and clean blade. After use, the blade should be thoroughly cleaned to maintain its effectiveness. Please exercise caution when handling the blades, as there is a risk of injury. Tetra strongly recommends to keep the tool out of reach of children at all times. Store the blade in a secure location when not in use to prevent accidental injuries. Additionally, please note that this product is not suitable for use with acrylic aquariums.