



⚓ Stay dry, stay confident—Rule 35A keeps your bilge in check effortlessly!
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 mercury-free, corrosion-resistant marine-grade materials, it ensures durability in saltwater and freshwater environments. Easy to install and engineered for precise activation, this switch protects vessels from flooding by automatically triggering the bilge pump at rising water levels. Trusted by boaters for over two decades, it offers peace of mind with a 2-year warranty and a strong reputation for long-term performance.




| ASIN | B000O8DA3M |
| Batteries Included? | No |
| Batteries Required? | No |
| Best Sellers Rank | #7,359 in Sports & Outdoors ( See Top 100 in Sports & Outdoors ) #3 in Boat Bilge Pumps |
| Brand | Rule |
| Color | White |
| Customer Reviews | 4.7 4.7 out of 5 stars (1,655) |
| Date First Available | October 1, 2001 |
| Global Trade Identification Number | 00042237095435 |
| Included Components | Rule 35A Rule-A-Matic Float Switch - 12-24 VDC |
| Is Discontinued By Manufacturer | No |
| Item Package Quantity | 1 |
| Item Weight | 4 ounces |
| Item model number | 35 |
| Manufacturer | Rule |
| Material | Plastic |
| Part Number | RM500B |
| Power Source | Corded Electric |
| Product Dimensions | 3.5"L x 5"W x 8.25"H |
| Size | Rule 35A Rule-A-Matic Bilge Pump Float Switch, Mercury Free |
| Special Features | Not_Performance_Used |
| Style | Bilge Pumps Switches |
| Switch Style | Float Switch |
| UPC | 696582485641 042237095435 617297076870 666668135845 042237083722 071030261204 773975400198 611104328671 779421381288 042237106230 014445389231 012304410966 826713868894 675904094815 072090742719 826713868900 963041571116 |
| Voltage | 12 Volts (DC) |
| Warranty Description | 2 years |
A**R
Feels solid and well made.
I have not yet installed it but the switch feels solid clicks so should be reliable, the hinge feels quality, small enough to fit almost everywhere. Vires are marine grade. Would buy again.
G**N
Best if normally kept dry.
8 Years so far. has worked very well. The trick to longevity is to place in a dry location. The float should trigger only as unusual water level is encountered. bolting it to the lowest point of the bilge where it will be forever submerged is probably the reason many are failing so early. Default to a location that indicates high water without needing to be wet all the time, and this will last many years. A small shim below giving some clearance from normal bilge height will go a long way.
J**.
Bad experience requires wise decisions
This device is top of the line, at least that is my experience. Though recently I had some problems when at the same time a 2000 GPH pump failed within two months of use even though it has a four years warranty. Amazon Rep told me that I would need to contact the manufacturer because my time warranty through Amazon would be only 30 days and from then on...I would need to contact the manufacturer. ( somewhere in China ) I understand Amazon policy, but honestly I expected more from this Co. And then it occurred that a cheap float switch failed 48 hours after installation. But it happens that the cost of installation is at least three times the cost of the device. So, I decided to go for RULE....to be on the safe side. This is my recommendation. to whoever needsto replace a damaged float switch that are always located as deep and unaccesible as the boat builder could install them....
M**L
Works as intended
Seems to work well. Would prefer if it turned on a bit sooner and was a pain to install on my boat, but that was not an issue with the pump. It is great that you can attach to your hull then snap in place. A product that you hope always works in an emergency.
D**L
Easy to use
Very easy to install and to power. Very fast to activate pump. Installed it in my bilge area and has not failed me
S**R
Works great
Works great
G**W
A dry bilge is a happy bilge
Works great Because its for a catamaran, I keep a couple spares on board.
R**N
Seitch
Works great no problems
D**L
As superb, quality float switch as is to be expected from Rule.
K**E
ich würde sehr gerne 0 Sterne für diesen Schrott geben, was aber nicht möglich ist. Vorher war 15 Jahre der gleiche Schwimmschalter im Boot. Auch damals hatte die Bodenplatte aufgegeben. Diesmal nach 3 Monaten stand ein bisschen Süsswasser in der Bilge. Die Bodenplatte ist völlig zerfallen. Billiger und Schrottiger kann man so ein Teil nicht konstruieren.
J**A
Funcionamiento y diseño perfecto, precio elevadisimo.
K**W
good and effective
J**.
Excelente
Trustpilot
2 months ago
2 weeks ago