K40 was a brand that was around for like 40 years I think. They officially closed their doors in Feb 2025. The only thing close to it, and several will say are much better is the Escort installed radar detectors.
Discreet and convenient, installed radar and laser detection systems give you the customization you need. Add features to create a custom driver alert system.
www.escortradar.com
The K40 I had installed comes with:
Front and Rear Radar modules handle FCC-controlled frequencies like X, K, KA, etc.
Front and Rear Laser Diffusers. These modules "bend" light, so it "blinds" the laser detector. These modules are always transmitting, so it's an active system rather than reactive. This means that I and those around me are "protected" from laser hits.
A remote control that lets you move through the voice menu.
Two tiny blue lights. The left light is front, right is rear. The lights tell me which direction the signal is coming from. The voice module tells me what band it is and the sounds tell me as well. However when an officer walks up - they see nor hear anything. The radar stops reporting when I come to a stop.
The next thing I always hear is:
“Oh, but isn’t that illegal?”
The answer? No. And here’s why:
The FDA has approved the use of lasers as a medical treatment. This is how lasers were introduced to the regulatory bodies. Unlike radar bands, which the FCC regulates, visible light isn’t subject to the same legal constraints. Mess with FCC-controlled frequencies, and yes, you’re looking at fines and potential trouble. But there’s no law against bending or adding light. That’s why diffusers and antilaser-based systems are legal.
Now, put aside the technical explanation and focus on reality: police don’t always care about what’s legal when they’re writing tickets. Even if what you're using is fully legal, it won’t stop them from citing you. If they
know you’re running something like a jammer or a shifter, that alone gives them more incentive to write you up and challenge you to fight it in court.
And if you go to court and tell them, then the first question out of their mouth is usually:
“Why do you have that if you’re not speeding?”
It’s a messed-up situation. You can be 100% in the right legally—but now you’ve just exposed that you’re actively trying to counter their tools. Whether it’s right or wrong doesn’t matter. They don’t like it.
I’ve only had one ticket—and it came from a cop who flat-out lied, claiming he tagged me with laser. Funny thing is, I had just installed the K40 system the day before and tested it. The
very next day after he wrote me that ticket, he tried to hit me again, and couldn’t get a reading. I rolled down the window and gave him a little wave like:
“Remember me, you lying MF?” - That was in Southlake, TX . The cop that wrote me the ticket is the #1 ticket writer for the PD, so they will defend their revenue generator. That is what the attorney told me. He knew the officer and he knew the situation. It wasn't the first time he heard people saying the cop was lying, but at that point, what can you do? Get it reduced, pay it, move on... K40 had a ticket guarantee, so they paid it.
It was very sad to see K40 close its doors nine days after I bought this one. I have been buying K40 integrated radar and laser diffusers for almost 20 years.
