The specification number is always complicated. If we search out a proper turn signals, can we as customer easily be informed of the difference between the numbers 3156 and 3157?

So you need to know this:


Can you tell which is 3156?

The Main Two Differences between Them


1. The Appearance

The turn signal 3156 has totally two wires, which is specifically called “single wire”. As for the one 3157, it has four wires called double wires. 



2. The Number of The Brightness Level

#3157 has two brightness levels

1. 3156 has only one brightness level.

3156 has two wires. The one is anode and the other is cathode which makes its brightness fixed.

NOTICE:3156 is set with “high brightness”.

2. 3157 has two brightness levels.

3157 has four wires. There are two same anodes and two cathodes for two levels of brightness.


3157 – higher brightness


3157 – low brightness

What is 3156 used as?

a. Turn signal

b. Reversing light

c. Light lamp


What about 3157?

a. Brake light

b. A Light used for both turn signal and light bub in a meantime
—see the video:

Which one shall I choose for turn signals, 3156 or 3157?

#It depends whether you need it for a single function or multifunction

Most cars in the market are equipped with turn signals for only turning the direction.

But in the rest of the market there are cars needing a light used as light bulbs, DRLs and turn signals in a meantime. Thereby the 3157 one is needed in this case. 



Q1. Can I install 3157 ones if my basement is literally 3157?

The signal 3157 can be installed onto the basement 3156. But on the contrary the signal 3156 is not for the basement 3157 because it is set with the function –two brightness levels.

…….We are collecting the questions. Feel free to make a messages below↓

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About Per-Accurate

We are a company providing LED light products for vehicles, e.g., headlights, light bulbs, turn lights and worklights. We have built a global supply chain from LED manufacturers to terminal clients. Besides, we also furnish LED products of the best quality with customers via Amazon, Ebay, Alibaba Express, Wish and our official shopping platform.

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