A standard bilge pump operates by a control switch that senses water and activates the pump. Rule Industries Rule-A-Matic Float Switch Plus with Shield and 12-24-32 VDC offers outstanding performance. Rule uses extra-large float chambers for increased buoyancy and detachable mounting bases that make them easier to install and remove for cleaning and inspection. All models are suitable for pumps that draw up to 20A, except the Model 35 Rule-A-Matic, which is suitable up to 14A. Year after year, the Rule-A-Matic Float Switch has been the switch of choice for boaters around the world. Rule Industries latest design now includes a removable base for easy cleaning and servicing, a mercury-free snap-switch tested to over one million cycles, and marine-grade blocked wire.