it is a carbide 3000 alarm system
Most of the time, cats are smart enough to take care of themselves. They'll get out of the way if a car comes. But you could try a collar with a different kind of reflector. I have seen some that have it all over the fabric.
You really shoudl make him come inside. Most of the time if he has been neutered, then you can get him to come insede at bed time offer him some treats or a little tiny bit of special food (mabye tuna) then lock him in the house with you at night time, make it his play time inside and he will start to look forward to spending that time with you. it is so much better for him there are many bad things that could happen to him when he is outside alone.
LEDs etc. are really not sufficient for drivers to see in the dark. The best thing is to either keep him in or just accept that he can look after himself. For security, microchipping is better, as collars can get caught on tree branches etc. or pulled off. I think you need to decide whether you want to give your cat freedom at night or have the peace of mind that he is safe.
Almost all surfaces reflect more light than a transparent one. A sheet of glass looks black except for one specific angle. ( angle of incidence angle of reflection) But a non smooth, non transparent one doesn't look black from any angle at all. And a smooth one generally reflects light with angle of incidence angle of reflection just as the transparent one does, but as light doesn't simply pass through the surface, most of it is reflected.
A reflective collar should do the trick. it's just the same as a normal collar just made out of reflective material, then there's nothing for him to loose off his collar.
