1Application: This sewage holding tank gauge is suitable for Rv, yacht, fishing boat, ship, easy to install, is a good replacement for your old or unsatifactory gauge. 2Multifunction: Applicable for sewage holding tank, accurately measure and display the water level of the sewage, let you know the sewage capacity at any time. 3Colorful Backlight: Built in backlight, the sewage holding tank gauge ensures visibility in any lighting conditions, allowing you to easily read liquid level information. 4Compact Size: The 2 inch (52 mm) holding tank level gauge is ideal for mounting on the dashboard of a vehicle or boat without taking up too much space. 5High Durability: The use of durable materials, with good shock and vibration resistance, can maintain reliability in a variety of harsh environments.