Rule Pumps Rule-A-Matic Plus 20 Amp 12 VDC Float Switch # 40 without fuse holder. It has a strong, fully integrated, impact resistant cover, which protects against debris and jamming. Wires exit out on the top to keep them out of the water. Manual testing feature allows for operations check. Use with pumps up to 20 amps. Environmentally friendly mercury-free design.