1797T20 7440 LED Turn Signal Lights Bulbs W21W WY21W Error Free No Anti Hyper Flash Amber Yellow Tail Lamps Front Rear Replacement Super Bright Projector 3014SMD 12V 21W 4 Pack

I'm an electronic engineer and I live in San Luis Potosi, SLP, Mexico, a city that is well known for its drivers who never use turn signal lights... ever, but I'm not one of them. I have a KIA Forte EX Premium 2019, and I always wanted to change my original halogen turn signal lights for some led bulbs. I searched a lot and found a lot of possible problems, the main problem, the hyperflash possibility, my electronic control unit (ECU) has CAN bus, so, the dashboard give me a warning if its detects a "problem" with the turn lights. Then the challenge was to find lights that behaved like the originals, but were LED lights. I decided to take risks with these lights, and I must say that I'm very satisfied, on the functional side, the lights are incredibly bright, much more than the original ones, I bought 2 kits and changed the 4 lights (front and rear), and despite the manufacturer's warnings, at least in my car didn't generate any hyperflash problems, and I didn't receive any warning on the dashboard. Speaking now on the technical side, they fulfill what they promote, the lights really demand practically the same current as a halogen one (but without the initial peak of current that a halogen had, almost 2.56 A), complying with the voltage and current ratio (power), resulting in the same 21 W (P=V*I). Just as a suggestion for those who buy them, try not to keep them on for a long time (5-8 minutes maximum I would say), since they really get hot due to the built-in resistor, but I think it wouldn't be very common to leave them on for a long time since they're usually used in maximum periods of approximately 30 seconds. I attach comparison images between a classic bulb and these LED bulbs, notice how the brightness of these LED lights is much higher.

Bought these, specifically because they supposedly had a built in load resistor, and I would avoid hyper flashing.The second I installed all 4, totally hyper flashing. the back two went in first, and with 2 normal blubs in line, they flashed slowly. Swapped in the front two...Hyperflash.Dunno about the quality of the bulbs other than this, but since this is why I bought these specific bulbs... 1 star.

The media could not be loaded.  These worked perfectly in my 2019 Mazda CX-5. I used them both front and rear, with no hyper flashing. It's great that the necessary resistors are built into the bulbs, no extra wiring necessary. These have a nice amber color to them (the best color for turn signals). The plastic base of the bulb does seem a little cheap, so time will tell how they hold up. If you pull them back out of the socket the wires on the bulb tend to get bent, so be careful. Overall, great for the price.

Four of these (PY21W) are installed in the turn signals of a 2005 Kawasaki ZZR1200 as part of a LED lighting upgrade. They are diffuse (lots of LEDs) lighting but are startlingly bright and I have no doubt these are going to be noticed, possibly even annoying to others at times. Four way flashers operate normally while the turn signals are hyper-flashing at about twice a second. Personally I prefer to be annoyingly bright than unnoticeable on two wheels, so they will stay, unless I get written up for them. Had similar joy with the 1157 red leds that I installed in the stop/running tail lights. LED is the only way to fly. Worth the price of admission.

It looks great! What can i say?Significantly brighter than incandescent and my old LED bulbs.Comparable to SIRIUSLED 7440s. At 1/3rd the price (these are $20 for 4, sirius is $60 for 4. (Same brightness, if anything siriusleds are brighter by the tiniest margin).HOWEVER, took a star off for build quality.Instead of boards, these look to either be glued off a sheet (like the double sided tapable led strips you buy on ebay), or it is double sided taped on. I dont see these lasting longevity wise, but we will see.... i also saw their glue run off the glass and onto a couple LEDs themselves.Either way, for brightness that it provides? I'll gladly pay $20.... i bought another pair for my wife's lexus as well!

This is ridiculous - it seems like the designers of this product thought that the more light it produces the better. But its really not. Bulbs are way too bright. At night you are being flared by them when they turn on. I was actually remarked on this by other drivers on the road - and they're right.I had to spray some color on them to dim them a bit.Build quality looks fine though.In a nutshell, I wasn't able to find bulbs that address this issue specifically and state that it produce same amount of lumens (or maybe slightly more) then regular incandescent bulbs. If you find such - prefer those over this product

These LED turn signal lamps were supposed to be hyper-flash free, however they would hyper-flash in my car most of the time. It seems possible it was a temperature issue, and on cold days more likely to hyper-flash than on a warm day (my tests was in November and it was a cold month).It is of course possible that in other vehicles the issue wouldn't occur. My car is a 2014 Hyundai Veloster.I was able to return them without issue (received Amazon credit).

These things are insanely bright! However, the thermal management of these is horrible. After only about 10 minutes of continuous use the bulbs overheated, overloaded the circuit blowing the fuse! Forcing me to drive home with absolutely no turn signals! Not happy!... After replacing the fuse the one bulb was very dim and extremely hot to the touch.Do yourself a favor and pay the money for some VLED Triton LED bulbs... You won't regret the high price of them. 😎👍