I've been using 3 of these for the past 3 or 4 years and never had a problem with them. Completely reliable, have never let me down come rain or shine.
Two stage sensitivity, a simple toggle on/off switch (which is great when setting up your bobbins so you don't annoy your neighbours), and the blue warning light is super bright. Blindingly bright!! You could turn your volume right down but won't miss anything cos you can see those lights from 100 yards away.
The other good thing about them is that they operate on 2 "cheap as chips buy anywhere" AAA batteries. So no trawling the shops looking for specialist ones.
You can add a transmitter to them and buy the receiver to match, but I have never bothered as I never move away from my rods far enough to have needed one.
My daughter has been so impressed with mine over the years that she has just bought 3 of her own, passing on her previous Chub ones to her boyfriend.
She much preferred the simple toggle on/off switch on mine, her old ones, (like a lot of others), had a push button switch and she was never sure if they were on or off.
You can tell when the Micron's are on just by glancing at them.
Recommended... highly.