---
product_id: 4139220
title: "Rule 35A Marine Rule-A-Matic Switch - 12V Automatic Bilge Pump Switch - Mercury Free, Durable, Reliable, and Easy to Install"
brand: "rule"
price: "€ 83.76"
currency: EUR
in_stock: true
reviews_count: 8
url: https://www.desertcart.es/products/4139220-rule-35a-marine-rule-a-matic-switch-12v-automatic-bilge
store_origin: ES
region: Spain
---

# 12V DC power for seamless integration Quick, hassle-free installation Mercury-free, corrosion-resistant marine-grade build Rule 35A Marine Rule-A-Matic Switch - 12V Automatic Bilge Pump Switch - Mercury Free, Durable, Reliable, and Easy to Install

**Brand:** rule
**Price:** € 83.76
**Availability:** ✅ In Stock

## Summary

> 🌊 Stay dry, stay ahead — the Rule 35A keeps your bilge in check effortlessly!

## Quick Answers

- **What is this?** Rule 35A Marine Rule-A-Matic Switch - 12V Automatic Bilge Pump Switch - Mercury Free, Durable, Reliable, and Easy to Install by rule
- **How much does it cost?** € 83.76 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.es](https://www.desertcart.es/products/4139220-rule-35a-marine-rule-a-matic-switch-12v-automatic-bilge)

## Best For

- rule enthusiasts

## Why This Product

- Trusted rule brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Plug & Play Setup:** Simple wiring and clear instructions get you sailing faster with zero fuss.
- • **Eco-Friendly & Safe:** Mercury-free design protects both your vessel and the environment.
- • **Dependable Performance:** Activates precisely when needed, whether docked or cruising open waters.
- • **Automatic Water Defense:** Hands-free bilge pump activation keeps your boat dry and flood-free.
- • **Marine-Grade Durability:** Built tough to resist corrosion and harsh saltwater conditions for long-lasting reliability.

## Overview

The Rule 35A Marine Rule-A-Matic Switch is a 12V automatic bilge pump float switch designed for reliable, hands-free water management on boats. Featuring a mercury-free, corrosion-resistant marine-grade construction, it ensures long-lasting durability in harsh environments. Easy to install with simple wiring, this switch activates your bilge pump automatically when water levels rise, providing peace of mind and protecting your vessel from flooding. Backed by a 2-year warranty, it’s the smart, eco-friendly choice for any boater.

## Description

Ensure your boat stays dry and protected with the Rule 35A Marine Rule-A-Matic Switch, a trusted solution for automatic bilge pump activation. Designed for seamless operation, this float switch automatically engages your bilge pump when water levels rise, providing hands-free water management and reducing the risk of flooding. Built with marine-grade materials, the mercury free Rule 35A is resistant to corrosion and harsh conditions, ensuring long-term durability and reliable performance in saltwater and freshwater environments. Its easy installation process makes it a practical choice for boat owners looking for a dependable, no-fuss solution to bilge water control. Whether you're a casual boater or a seasoned mariner, the Rule 35A Automatic Bilge Pump Switch offers peace of mind by keeping your bilge dry and your vessel safe. Pair it with a compatible 12V bilge pump for effortless water management on every journey.

## Features

- Reliable Automatic Bilge Control: The Rule 35A Marine Rule-A-Matic Switch ensures automatic activation of your bilge pump when water levels rise, preventing manual checks and safeguarding your vessel against unexpected water accumulation.
- Durable, Marine-Grade Construction: Built to withstand harsh marine environments, this bilge pump switch is mercury free and features corrosion-resistant components, including a robust housing and high-quality wiring, ensuring long-lasting performance.
- Easy Installation for Hassle-Free Use: Designed for straightforward setup, the Rule-A-Matic switch integrates seamlessly into your boat's bilge system. With simple wiring and clear instructions, installation is quick and convenient.
- Dependable Performance in Every Condition: Engineered for reliability, this float switch activates your bilge pump precisely when needed, ensuring smooth operation whether you’re at the dock or on open water.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| Brand | Rule |
| Color | White |
| Material | Plastic |
| Style | Bilge Pumps Switches |
| Product Dimensions | 3.5"L x 5"W x 8.25"H |
| Power Source | Corded Electric |
| Item Weight | 4 ounces |
| Voltage | 12 Volts (DC) |
| Global Trade Identification Number | 00042237095435 |
| Manufacturer | Rule |
| UPC | 696582485641 042237095435 617297076870 666668135845 042237083722 071030261204 773975400198 611104328671 779421381288 042237106230 014445389231 012304410966 826713868894 675904094815 072090742719 826713868900 963041571116 |
| Part Number | RM500B |
| Item model number | 35 |
| Is Discontinued By Manufacturer | No |
| Size | Rule 35A Rule-A-Matic Bilge Pump Float Switch, Mercury Free |
| Item Package Quantity | 1 |
| Switch Style | Float Switch |
| Included Components | Rule 35A Rule-A-Matic Float Switch - 12-24 VDC |
| Batteries Included? | No |
| Batteries Required? | No |
| Warranty Description | 2 years |

## Product Details

- **Brand:** Rule
- **Color:** White
- **Material:** Plastic
- **Style:** Bilge Pumps Switches
- **Product Dimensions:** 3.5"L x 5"W x 8.25"H
- **Power Source:** Corded Electric
- **Item Weight:** 4 ounces
- **Voltage:** 12 Volts (DC)
- **Global Trade Identification Number:** 00042237095435
- **Manufacturer:** Rule

## Images

![Rule 35A Marine Rule-A-Matic Switch - 12V Automatic Bilge Pump Switch - Mercury Free, Durable, Reliable, and Easy to Install - Image 1](https://m.media-amazon.com/images/I/41fUsHCz1QL.jpg)

## Available Options

This product comes in different **Style** options.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Nice switch. Installs fairly easy.
*by M***Y on April 23, 2020*

Works great. Make sure you don't reverse the wires. They are the same color. But can only be hooked up one way. Instructions don't specify which wire is which. Test before committing to install. Connect one grey wire to the battery. Then use a voltmeter to verify 12v power comes through. If no 12v, it's backwards. Reverse the grey wires. Test again. One grey wire goes to the battery, one goes to the pump. Brown wire is positive on the pump in my case. Black wire on the pump is ground.

### ⭐⭐⭐⭐⭐ Good switch, problem free delivery
*by E***K on May 13, 2025*

Excellent switch. Quickly installed it, away I went.

### ⭐⭐⭐⭐⭐ Works fine
*by D***A on July 27, 2023*

These are much nicer to install compared to the older switches -kind big for smaller boats-the removable base make rigging simple -have had better luck with these compared to the super switches rule sells-

## Frequently Bought Together

- Rule 35A Marine Rule-A-Matic Switch (Mercury Free)
- Rule High-Performance 1500GPH, 12 Volt Water Pump for Boats - Bilge Pump with Pressure Switch, Submersible Pump, and Float Switch - Ideal for Marine Accessories, Boating supplies, and Bilge Pumps
- Rule 2000 GPH Bilge Pump 12V - Submersible Marine Boat Accessory with 1-1/8" Discharge, Anti-Airlock, Reliable Ignition Protection, Silent Operation, Easy-Clean Strainer - Rust/Corrosion Resistant

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**Shop now:** [https://www.desertcart.es/products/4139220-rule-35a-marine-rule-a-matic-switch-12v-automatic-bilge](https://www.desertcart.es/products/4139220-rule-35a-marine-rule-a-matic-switch-12v-automatic-bilge)

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*Product available on Desertcart Spain*
*Store origin: ES*
*Last updated: 2026-01-23*