Aetna Engineering
Precision digital tachometers, shaft-speed instruments, senders, and sensors for marine and industrial RPM monitoring.
Aetna Engineering, manufactured by Fireboy-Xintex, produces solid-state digital engine and shaft tachometers, mechanical senders, magnetic sensors, and installation accessories. Its Classic Series instruments are permanently calibrated and designed for precise RPM readings, helping operators synchronize engines and find efficient operating speeds.
Products from Aetna Engineering
51 products
Usually ships 3-5 daysAetna EngineeringAetna 8402R-P-H-DS Red LED Auto-Dimming Digital Tachometer
Tachometer, round, red LED display with automatic low-light dimming, polished stainless steel bezel (P) With LCD hour meter, for use on diesel engine.
SKU AET-8402R-P-H-DS
$345.00MSRP $405.00- Usually ships 3-5 daysAetna Engineering
Aetna 8402R-P-H-G Red LED Auto-Dimming Digital Tachometer
Tachometer, round, red LED display with automatic low-light dimming, polished stainless steel bezel (P) With LCD hour meter, for use on gas engine.
SKU AET-8402R-P-H-G
$345.00MSRP $405.00 
Aetna EngineeringAetna 8619 Tachometer Drive Adapter
Adapter, tachometer drive, Lehman.
SKU AET-8619
$150.00MSRP $175.00
Aetna EngineeringAetna 8709 Magnetic Sensor Kit
Magnetic sensor kit (for custom application on diesel engine w/ no tach drive).
SKU AET-8709
$115.00MSRP $135.00
Aetna EngineeringAetna 8875 Tachometer Drive Adapter
Adapter, tachometer drive, Perkins.
SKU AET-8875
$310.00MSRP $360.00
Aetna EngineeringAetna 8901-D Mechanical Tachometer Sender
Sender, mech. driven, fits DIN tach drives on diesel engines.
SKU AET-8901-D
$325.00MSRP $380.00Aetna 8901-H Mechanical Tachometer Sender
Sender, mechanically driven, high voltage output, fits most tach drives on diesel engines.
SKU AET-8901-H
$325.00MSRP $380.00Aetna 8901-M Mechanical Tachometer Sender
Sender, mech. driven, fits metric tach drives on diesel engines.
SKU AET-8901-M
$325.00MSRP $380.00
Aetna EngineeringAetna 8902-D Mechanical Tachometer Sender
Sender, mech. driven, (dual output with DIN drive for diesel engines).
SKU AET-8902-D
$355.00MSRP $415.00- Usually ships 3-5 daysAetna Engineering
Aetna 8905R-B-Dir-DS LCD Red-Backlit Digital Tachometer
Tachometer, round, LCD display with red backlight, black anodized aluminum bezel (B) direction indicating, for use with SS-2 or SS-3 sensor.
SKU AET-8905R-B-Dir-DS
$450.00MSRP $525.00 
Aetna EngineeringAetna 8905R-B-G LCD Red-Backlit Digital Tachometer
Tachometer, round, LCD display with red backlight, black anodized aluminum bezel (B) For use on gas engine.
SKU AET-8905R-B-G
$325.00MSRP $380.00- Usually ships 3-5 daysAetna Engineering
Aetna 8905R-B-H-G LCD Red-Backlit Digital Tachometer
Tachometer, round, LCD display with red backlight, black anodized aluminum bezel (B) With LCD hour meter, for use on gas engines.
SKU AET-8905R-B-H-G
$360.00MSRP $420.00 - Usually ships 3-5 daysAetna Engineering
Aetna 8905R-B-H-WP-DS LCD Red-Backlit Digital Tachometer
Tachometer, round, LCD display with red backlight, black anodized aluminum bezel, w/LCD Hour Meter, Sensitive, Waterproof.
SKU AET-8905R-B-H-WP-DS
$480.00MSRP $560.00 - Usually ships 3-5 daysAetna Engineering
Aetna 8905R-B-USCG-DS LCD Red-Backlit Digital Tachometer
Tachometer, round, LCD display with red backlight, black anodized aluminum bezel, Sensitive, Waterproof, Remote Dimming, Set to 4.1 PPR.
SKU AET-8905R-B-USCG-DS
$480.00MSRP $560.00 - Usually ships 3-5 daysAetna Engineering
Aetna 8905R-P-DS LCD Red-Backlit Digital Tachometer
Tachometer, round, LCD display with red backlight, polished stainless steel bezel (P) For use on diesel engine.
SKU AET-8905R-P-DS
$325.00MSRP $380.00 - Usually ships 3-5 daysAetna Engineering
Aetna 8905R-P-Dir-DS LCD Red-Backlit Digital Tachometer
Tachometer, round, LCD display with red backlight, polished stainless steel bezel (P), direction indicating, for use with SS-2 or SS-3 sensor.
SKU AET-8905R-P-Dir-DS
$450.00MSRP $525.00 - Usually ships 3-5 daysAetna Engineering
Aetna 8905R-P-G LCD Red-Backlit Digital Tachometer
Tachometer, round, LCD display with red backlight, polished stainless steel bezel (P) For use on gas engine.
SKU AET-8905R-P-G
$325.00MSRP $380.00 
Aetna EngineeringAetna 8905R-P-H-G LCD Red-Backlit Digital Tachometer
Tachometer, round, LCD display with red backlight, polished stainless steel bezel (P) With LCD hour meter, for use on gas engine.
SKU AET-8905R-P-H-G
$360.00MSRP $420.00
Aetna EngineeringAetna 8912 Flywheel Gear Sensor
Flywheel gear sensor (same as 8910 with dual output).
SKU AET-8912
$235.00MSRP $275.00- Usually ships 3-5 daysAetna Engineering
Aetna 8932 Ballast Resistor
32 Volt ballast resistor (drops overall current to 12v dc).
SKU AET-8932
$9.00MSRP $11.00 
Aetna EngineeringAetna 9212 Sender Drive Extension
Drive extension, sender, 1.50" long.
SKU AET-9212
$60.00MSRP $70.00- Usually ships 3-5 daysAetna Engineering
Aetna 9220 Flexible Drive Pin
Flexible drive pin, 3" long, 0.187" x 0.187".
SKU AET-9220
$75.00MSRP $90.00 
Aetna EngineeringAetna SS-1 Speed Sensor
Proximity hall effect sensor, 5 mm range (for measuring shaft RPM).
SKU AET-SS-1
$270.00MSRP $315.00Aetna SS-1-8 Speed Sensor
Proximity hall effect sensor, 8 mm range (for measuring shaft RPM).
SKU AET-SS-1-8
$355.00MSRP $415.00
Choose the right Aetna tachometer system
Start with the display style and application: 8402R models use bright LED readouts, while 8905R models use LCD displays. Match the instrument to a gas engine, diesel engine, or direction-indicating shaft installation, then select the compatible sender, sensor, drive adapter, and wiring accessories.
Accurate RPM monitoring for marine engines and shafts
Aetna Engineering instruments are manufactured by Fireboy-Xintex for precise engine-speed and shaft-speed monitoring. The solid-state designs are permanently calibrated and have no moving display parts to stick or wear out.
- Digital engine and shaft tachometers
- LED and LCD display options
- Mechanical senders and magnetic speed sensors
- Drive adapters, reducers, trim rings, and installation accessories
Frequently asked questions
Who manufactures Aetna Engineering products?
Aetna Engineering products are manufactured by Fireboy-Xintex. Aetna is the instrumentation brand used for its digital tachometers, shaft tachometers, senders, sensors, and related accessories.
What is the difference between Aetna 8402R and 8905R tachometers?
The 8402R Series uses a red LED display, while the 8905R Series uses an LCD display. Both families include models for specific engine, bezel, hour-meter, and direction-indicating applications, so the complete part number matters.
How do I choose a sender or sensor for an Aetna tachometer?
Match the sender or sensor to the tachometer model and the engine or shaft pickup method. Check the full Aetna part number and installation requirements before ordering; contact our technical team if you need help confirming compatibility.
Need a quote on Aetna Engineering gear?
Tell us what you're building. Our team will spec the right kit for your install and send a written quote.
Why buy from us
We carry this brand because it earns its place on the boat.
Stocked for marine builds
We focus on parts that meet the conditions boats see — not just whatever ships fastest.
Engineering review on request
Send a parts list or a layout and we'll check it against your boat before you order.
Direct from our team
Pricing, availability, and product questions all go through the same people who build custom harnesses and panels.