The MadMan CLD SA is a Stand Alone coolant level detector for use in any situation where you want to monitor water/coolant level such as a vehicle's cooling system or water tank. The unit uses two steel self tapping screws as water probes. The unit has an audible alarm as well as led indicator. It also has a silence / deactivate button. It can also be used in conjunction with the earlier range of EMS units (Blue Buttons) which do not have built-in CLD functions.