Uniden, Escort or Valentime
However, since most jurisdictions use Lidar, it's usefulness is limited. Lidar does not emit a detectable signal before it bounces off your vehicle. So you're toast.
I have been running a Valentine 1 Gen 2 for the last three years. I have about a 70 to 1 ratio of non-lidar to lidar hits. Been directly tagged three times with Lidar in known locations where I slow down anyway vs the hundreds of times the V1G1 has informed me of police presence before I am in their range, whether they are looking for speeders or not.
The challenges include:
1. How do you mount it?
2. How do you protect it from water?
3. How do you protect it from too much heat?
4. How do you get alerted while focusing on the road with ear plugs in?
5. How do you filter out all the mobile false signals from the new car's safety suites and self adjusting cruise control.
6. How do you keep it from screwing up the gps signal reception on your BMW Nav 5 GPS? (This was my biggest challenge).
4 and 5 are resolved by using the V1G2 with one of the many radar apps. I currently use Companion which provides additional filtering, spoken alerts, location filtering and will soon have carplay integration. I can listen to it with my Cardo.
The need for this is largely driven by where you ride and how fast you ride. I spend most of my miles on multi-day trips across the westen states on backroads. I find being made aware of police presence before I can see them helpful in keeping me focused on riding and avoiding awards.
I find that rdforums.org and vortex radar to be great sources of information.
Flip