quality parts from what I can tell, first three hours no issues. 
Cw E
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Sky-Tec Sts-M12 Battery/Master Solenoid By Lamar
September 18, 2025
 
Correct part with the proper type certificate and fully operational in my aircraft. C172F
Jaspal 
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Sky-Tec Sts-M12 Battery/Master Solenoid By Lamar
August 19, 2025
 
fits well and works well
Robert L
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Sky-Tec Sts-M12 Battery/Master Solenoid By Lamar
March 9, 2025
 
Old technology that works like a charm🏆
James D
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Sky-Tec Sts-M12 Battery/Master Solenoid By Lamar
February 7, 2025
 
Working normal so far in 76 Grumman as an oem replacement. 
West T
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Sky-Tec Sts-M12 Battery/Master Solenoid By Lamar
January 28, 2025
 
Excellent
Jean L
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Verified Purchase
Sky-Tec Sts-M12 Battery/Master Solenoid By Lamar
January 22, 2025
 
So far it’s working as planned.  I also replaced my battery with EarthX the engine turns over much faster.  
Cory H
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Sky-Tec Sts-M12 Battery/Master Solenoid By Lamar
November 12, 2024
 
Showed up on time and was the correct part
Tony M
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Sky-Tec Sts-M12 Battery/Master Solenoid By Lamar
October 30, 2024
 
Reasonable price for an AC part!
Robert S
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Sky-Tec Sts-M12 Battery/Master Solenoid By Lamar
June 25, 2024
 
Joseph J
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Verified Purchase
Sky-Tec Sts-M12 Battery/Master Solenoid By Lamar
June 12, 2024
 
Drop in replacement on my 1959 Cessna 180, functions as required, timely delivery, fair price. Thank you Aircraft Spruce.
Charles W
 Verified Purchase
Verified Purchase
Sky-Tec Sts-M12 Battery/Master Solenoid By Lamar
May 15, 2024
 
This was a simple drop-in install on my 74 A185F. Comes with wiring diagram.  Looks like quality construction and works as advertised for my 12V system.  Hope it lasts the coming 49 years, like the original.
Michael B
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Sky-Tec Sts-M12 Battery/Master Solenoid By Lamar
December 19, 2023
 
Excellent product!
Gail A
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Sky-Tec Sts-M12 Battery/Master Solenoid By Lamar
September 28, 2023
 
The product was as advertised 
Thomas J
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Verified Purchase
Sky-Tec Sts-M12 Battery/Master Solenoid By Lamar
April 28, 2023
 
Las V
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Verified Purchase
Sky-Tec Sts-M12 Battery/Master Solenoid By Lamar
April 4, 2023
 
Great product.
John B
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Sky-Tec Sts-M12 Battery/Master Solenoid By Lamar
March 4, 2023
 
Great product and wonderful product support from Aircraft Spruce
Bob C
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Sky-Tec Sts-M12 Battery/Master Solenoid By Lamar
October 14, 2022
 
Magaero L
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Verified Purchase
Sky-Tec Sts-M12 Battery/Master Solenoid By Lamar
October 4, 2022
 
My Lycoming I0360A1B6 was cranking like I had a failing battery.  The SKY-TEC STS-M12 returned my cranking RPM like a brained battery.
Danny K
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Sky-Tec Sts-M12 Battery/Master Solenoid By Lamar
September 21, 2022
 
Pafok O
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Sky-Tec Sts-M12 Battery/Master Solenoid By Lamar
July 5, 2022
 
Simple. Fits. Works. 
Brent P
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Sky-Tec Sts-M12 Battery/Master Solenoid By Lamar
June 29, 2022
 
Works well. Be careful of your wiring as this unit is different than original. 
Joseph J
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Sky-Tec Sts-M12 Battery/Master Solenoid By Lamar
June 17, 2022
 
Purchased but havent yet installed
Jeanne G
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Sky-Tec Sts-M12 Battery/Master Solenoid By Lamar
June 15, 2022
 
Product worked as expected shipping was on time as expected. I would buy it again if needed and recommended this product. My application was on a C-150 H 
Nelson P
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Verified Purchase
Sky-Tec Sts-M12 Battery/Master Solenoid By Lamar
March 19, 2022
 
Replaced my original master/battery solenoid on my RV10 with this one. With my high CCA Li battery I needed the high in-rush this product provided versus replacing with cheaper versions. Included wiring diagram helped with install. Original was a 3-post. This is a 4-post. Still early in trying out phase but so good, so far
Dale C
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Sky-Tec Sts-M12 Battery/Master Solenoid By Lamar
December 10, 2021
 
great service and shipping time 
Epic H
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Sky-Tec Sts-M12 Battery/Master Solenoid By Lamar
October 27, 2021
 
Good quality & good pricing. 
Keith M
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Sky-Tec Sts-M12 Battery/Master Solenoid By Lamar
October 16, 2021
 
Perfect fit in my 1958 Cessna 175
Nathan J
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Verified Purchase
Sky-Tec Sts-M12 Battery/Master Solenoid By Lamar
May 21, 2021
 
Silver contacts should give good service 
James C
March 15, 2021
 
Performed exactly as advertised. Quality product. Outstanding service.
Dennis E
December 22, 2020
 
Fits & functions fine.
Ken S
October 23, 2020
 
A perfect replacement for the 3 post contactor on my Cessna 150.  
Serloyd L
October 2, 2020
 
Exact fit and replacement for my old one.   Works perfectly so far.  
Richard C
August 17, 2020
 
      Product came as Advertised. As always I never had any problems with the great service Aircraft Spruce provides. Thanks 
Peter S
June 8, 2020
 
so far so good
Richard J
March 15, 2020
 
Good fit. Solid construction. No more jiggling battery leads to get relay to engage.
Steven A
February 19, 2020
 
     to replace an original equipment solenoid in my OLD Mooney, this is the only game in town (and at a reasonable price too).  it fit just fine and operates exactly as expected.  as usual, no complaints with anything from Aircraft Spruce. 
T. D
March 7, 2019
 
   Just Fine   
Caseydon 
February 3, 2019
 
  This product fit in the mount and to this point accomplishes the intended task at a fraction of the OEM part.     
Gary 
July 20, 2018
 
Ric H
 Verified Purchase
Verified Purchase
Sky-Tec Sts-M12 Battery/Master Solenoid By Lamar
May 10, 2024
 
Good Part-  standard replacement.
Db 
May 14, 2020
 
Installation was easy.
Works exactly like the unit replaced. Unknown durability as just installed
Chris G
 Verified Purchase
Verified Purchase
Sky-Tec Sts-M12 Battery/Master Solenoid By Lamar
February 15, 2022
 
This is not a direct replacement for a master solenoid.  This product takes advanced knowledge to wire it correctly and the directions provide are as clear as mud. 
Scott P
 Verified Purchase
Verified Purchase
Sky-Tec Sts-M12 Battery/Master Solenoid By Lamar
October 26, 2023
 
Replaced old solenoid after I was having starting issues. This performed better at first then the same performance later. A month ago it totally failed in Northern Maine on a very cold day- had to bypass to get out of there. Long of the short: This isnt worth the money. Still fails, when you least want it to. 
Lb 
February 23, 2022
 
    We installed them on 3 of the Cessnas in our rental fleet. Had problems with one of them dropping out in flight. Complied with the service bulletin and Hartzell sent 3 new units.  One of the new units in a Cessna 150 failed ON after about  60 hrs.  We were able to bring a flat battery back. Hartzell replaced the unit for free. The replacement unit has now also failed ON after 45 hrs.   
Cas L
September 12, 2018
 
These suck lasted about a month. Got another, same thing.
Andrew H
July 18, 2025
 
This is the 3 unit in 3 years 
Sure wish I could find another manufacturer 
Mark D
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Verified Purchase
Sky-Tec Sts-M12 Battery/Master Solenoid By Lamar
May 24, 2023
 
Ever since Ive installed this contactor, Ive had an intermittent issue where the master doesnt always turn off if the engine is hot. When the engine cools off again, the master turns off.
Louis L
November 22, 2020
 
This is a replacement for an identical master solenoid (STS-M12) that was in operation for less than 6 months. The previous solenoid would make a loud click when I turn it on but would not make contact across the primary voltage wires. This would happen intermittently. I inspected all connections and battery - which were all like new. 
The description states the Silver Contacts provide 300A in-rush & 150A continuous-duty capability Much higher than OE units.     I removed the cap on the solenoid and did not see any silver contacts - They are copper contacts. I would like to have an explanation of what do they consider silver contacts. I certainly did not find silver inside. Very disappointing.
Richard G
July 2, 2020
 
      Installed in my E-AB. Aircraft is yet to fly and this product failed with under 100 cycles of use. Only has been turned on to test/calibrate. Solenoid actuates but the contacts internally have glazed and it does not permit power to flow through. Shows 13.6 VDC in but 0.22 VDC out. Would not purchase again. 
Charlie 
May 22, 2019