Using this Brizo Invari Widespread Lavatory Handle Kit is a breeze. Just turn the black crystal knobs to adjust the water flow and temperature. For installation, make sure your sink is a widespread lavatory type as the kit is designed for it. When it comes to maintenance, use a soft cloth to clean the brass body and the black crystal knobs regularly. Avoid using abrasive cleaners as they might scratch the surface. Also, if you notice any water leakage, check the connections to ensure they are tight. With proper use and care, this handle kit will serve you well for a long time.