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Metra 40-GM21 Antenna Adapter

Works with select 1987-up General Motors vehicles — factory male to female Motorola antenna connector

15 Reviews

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Item # 12040GM21

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Metra 40-GM21 adapter

The Metra 40-GM21 adapter lets you connect an aftermarket antenna cable to the factory radio. It has a female Motorola plug on one end and a right angled male GM antenna plug on the other. This adapter can also be used when installing a wired FM modulator with the factory radio. Please enter your vehicle information or call an Advisor at 1-888-955-6000 to find out if this adapter is compatible with your vehicle. Warranty: 60 days.

Exact fit. High quality and fast shipping. I have been buying from Crutchfield since I was a teenager and I will continue to buy from them.

Jeremy L., Swansboro, NC

What's in the Box:

  • 6.438" antenna adapter cable (one end terminating in a female Motorola plug and the other end terminating in a right angled male GM antenna plug).

Metra 40-GM21 Antenna Adapter Reviews

Average Customer Review(s):

(15 Reviews)
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Product Research


Compatibility: 1987 and later GM factory radio with mini connector to universal antenna adapter cable (factory radio to universal antenna)

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Q & A

Customer Q&A

Crutchfield asked  
Why did you buy this?

Fits my truck [ phillip  Aug 14, 2016 ]
My goal is to add an AUX port to the factory installed stereo system. This item is one of two items needed to complete this goal in my 2005 Pontiac G6 GT. [ Paul  Jul 29, 2016 ]
I choose one but both showed up on the order. If I don't need both delete whichever one is not needed. Thanks John [ Tech Brown  Jun 12, 2016 ]
price [ ronald  Jan 12, 2016 ]

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